Introduction

NOTE: For Specifications with illustrations, make reference to Specification For 3406C Generator Set Engine, SENR1107. If the Specifications in SENR1107 are not the same as the Systems Operation, Testing & Adjusting, look at the printing date on the front cover of each book. Use the Specifications given in the book with the latest date.

Troubleshooting

Troubleshooting can be difficult. The Troubleshooting Problem List gives a list of possible problems. To make a repair to a problem, make reference to the cause and correction on the pages that follow.

This list of problems, causes, and corrections will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list.

Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list is only a guide and cannot give all possible problems and corrections. The service personnel must find the problem and its source, then make the necessary repairs.

1. Engine Crankshaft Will Not Turn When Start Switch Is On.

2. Engine Will Not Start.

3. Engine Misfires Or Runs Rough.

4. Stall At Low RPM.

5. Sudden Changes In Engine RPM.

6. Not Enough Power.

7. Too Much Vibration.

8. Loud Combustion Noise.

9. Valve Train Noise (Clicking).

10. Oil In Cooling System.

11. Mechanical Noise (Knock) In Engine.

12. Fuel Consumption Too High.

13. Loud Valve Train Noise.

14. Too Much Valve Lash.

15. Valve Rotocoil Or Spring Lock Is Free.

16. Oil At The Exhaust.

17. Little Or No Valve Lash.

18. Engine Has Early Wear.

19. Coolant In Lubrication Oil.

20. Too Much Black Or Gray Smoke.

21. Too Much White Or Blue Smoke.

22. Engine Has Low Oil Pressure.

23. Engine Uses Too Much Lubrication Oil.

24. Engine Coolant Is Too Hot.

25. Exhaust Temperature Is Too High.

26. Starting Motor Does Not Turn.

27. Alternator Gives No Charge.

28. Alternator Charge Rate Is Low Or Not Regular.

29. Alternator Charge Is Too High.

30. Alternator Has Noise.

31. Rack Solenoid Does Not Stop Engine.

Problem 1: Engine Crankshaft Will Not Turn When Start Switch Is On

Probable Cause:

1. Battery Has Low Output

Make Reference to Problem 26.

2. Wires Or Switches Have Defect

Make Reference to Problem 26.

3. Starting Motor Solenoid Has A Defect

Make Reference to Problem 26.

4. Starting Motor Has A Defect

Make Reference to Problem 26.

5. Inside Problem Prevents Engine Crankshaft From Turning

If the crankshaft can not be turned after the driven equipment is disconnected, remove the fuel injection nozzles and check for fluid in the cylinders when the crankshaft is turned. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, piston seizure, or wrong pistons installed in the engine.

Problem 2: Engine Will Not Start

Probable Cause:

1. Starting Motor Turns Too Slow

Make reference to Problem 27.

2. Dirty Fuel Filter

Install new fuel filter.

3. Dirty Or Broken Fuel Lines

Clean or install new fuel lines as necessary.

4. Fuel Transfer Pump

At starting rpm, the minimum fuel pressure for fuel transfer pump must be 20 kPa (3 psi). If fuel pressure is less than 20 kPa (3 psi), change the fuel filter element. Look for air in the fuel system. If fuel pressure is still low, install a new fuel transfer pump.

5. No Fuel To Cylinders

Put fuel in fuel tank. "Prime" (remove the air and/or poor quality fuel) the fuel system.

6. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. See Diesel Fuels and Your Engine, SEBD0717.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

8. Shutoff Solenoid Will Not Move To Extended Position

The solenoid must get electricity to stop the engine. Operate the control for the shutoff solenoid and see if the solenoid makes a noise (clicking sound). If this sound can be heard and the engine will not start, remove the solenoid. Now see if the engine will start. If the engine starts, the shutoff solenoid either needs an adjustment or it is defective and replacement of the solenoid is necessary.

Problem 3: Engine Misfires Or Runs Rough

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure.

If fuel pressure is lower than 170 kPa (25 psi) install a new filter element. The outlet pressure of the fuel transfer pump at full load must be 240 kPa (35 psi). If fuel pressure is still low, install a new fuel transfer pump.

2. Air In Fuel System

Find the air leak in the fuel system and correct it. If air is in the fuel system, it will probably get in on the suction side of fuel transfer pump.

3. Leak Or Break In Fuel Line Between Injection Pump And Fuel Injection Nozzle

Install a new fuel line.

4. Wrong Valve Lash.

Make adjustment according to the Subject, Valve Lash Setting.

5. Defect In Fuel Injection Nozzle(s) Or Injection Pump(s)

Run engine at rpm that misfires the most and runs the roughest. Then loosen a fuel line nut on the fuel injection nozzle for each cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump and fuel injection nozzle for that cylinder. Install new parts where needed.

6. Wrong Fuel Injection Timing

Make adjustment to timing.

7. Bent Or Broken Push Rod

Replacement of push rod is necessary.

8. Fuel Has "Cloud Point" Higher Than Atmospheric Temperature ("Cloud Point"=Temperature Which Makes Wax Form In Fuel).

Drain the fuel tank, lines, and fuel injection pump housing. Change the fuel filter. Fill the tank with fuel which has the correct "cloud point" and remove the air from the system with the priming pump.

Problem 4: Stall At Low RPM

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure.

If fuel pressure is lower than 170 kPa (25 psi) install a new fuel filter element. The outlet pressure of the fuel transfer pump at full load must be 240 kPa (35 psi). If fuel pressure is still low, install a new fuel transfer pump.

2. Idle RPM Too Low

Make adjustment to governor so idle rpm is the same as given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

3. Defect In Fuel Injection Nozzle(s)

Install a new fuel injection nozzle.

4. Engine Accessories

Check engine accessories for damage and correct adjustment. If necessary, disconnect the accessories and test the engine.

5. Defect In Fuel Injection Pump(s)

Install new parts if needed.

Problem 5: Sudden Changes In Engine Speed (rpm)

Probable Cause:

1. Failure Of Governor Or Fuel Injection Pump

Look for damaged or broken springs, linkage or other parts. Remove the governor. Check for free travel of fuel rack. Be sure fuel injection pumps are installed correctly. Check for correct governor spring. Install new parts for those that have damage or defects.

Problem 6: Not Enough Power

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank.

2. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or bad bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure.

If fuel pressure is lower than 170 kPa (25 psi) install a new fuel filter element. The outlet pressure of the fuel transfer pump at full load must be 240 kPa (35 psi). If fuel pressure is still low, install a new fuel transfer pump.

3. Leaks In Air Inlet System

Check the pressure in the air inlet manifold. Look for restrictions in the air cleaner.

4. Governor Linkage

Make adjustment to get full travel of linkage. Install new parts for those that have damage or defects.

5. Wrong Valve Lash

Make adjustment according to the Subject, Valve Lash Setting.

6. Defect In Fuel Injection Nozzle(s) Or Fuel Injection Pumps

Run engine at rpm that misfires the most or runs the roughest. Then loosen a fuel line nut on the injection pump for each cylinder, one at a time. Find the cylinder where a loosened fuel line nut does not change the way the engine runs. Test the injection pump and fuel injection nozzle for that cylinder. Install new parts where needed.

7. Wrong Fuel Injection Timing

Make adjustment to timing.

8. Rack Setting Too Low

Make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

9. Defect In Aftercooler

Check temperature of inlet and outlet water supply. Remove any external or internal restrictions.

10. Fuel Ratio Control

Control either needs an adjustment or it is damaged and a new control is needed.

11. Turbocharger Has Carbon Deposits Or Other Causes Of Friction

Make inspection and repair of turbocharger as necessary.

Problem 7: Too Much Vibration

Probable Cause:

1. Loose Bolt Or Nut For Pulley Or Damper

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect

Install a new pulley or damper.

3. Engine Supports Are Loose, Worn, Or Have A Defect

Tighten all bolts that hold engine supports. Install new components if necessary.

4. Engine Misfires Or Runs Rough

Make Reference to Problem 3.

Problem 8: Loud Combustion Noise (Sound)

Probable Cause:

1. Poor Quality Fuel

Remove the fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. See Diesel Fuels and Your Engine, SEBD0717.

2. Defect In Fuel Injection Nozzle(s)

Install new fuel injection nozzle(s).

3. Defect In Fuel Injection Pump(s)

Install new fuel injection pump(s).

4. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 9: Valve Train Noise (Clicking)

Probable Cause:

1. Damage To Valve Spring(s), Locks Or Broken Or Worn Valve Lifter

Install new parts where necessary. Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow of oil at low rpm. Oil passages must be clean, especially those that send oil to the cylinder head.

3. Too Much Valve Lash

Make adjustment according to the Subject, Valve Lash Setting

4. Damage In Bridge For Valves

Make a replacement of the bridge and make an adjustment as necessary.

Problem 10: Oil In Cooling System

Probable Cause:

1. Defect In Core Of Engine Oil Cooler

Install a new engine oil cooler.

2. Failure Of Cylinder Head Gasket Or Water Seals

Install a new head gasket and new water seals in spacer plate.

Problem 11: Mechanical Noise (Knock) In Engine

Probable Cause:

1. Failure Of Bearing For Connecting Rod

Inspect the bearing for the connecting rod and the bearing surface (journal) on the crankshaft. Install new parts where necessary.

2. Damaged Timing Gears

Install new parts where necessary.

3. Damaged Crankshaft

Make replacement of the crankshaft.

4. Defect In Attachment

Repair or install new components.

Problem 12: Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks

Tighten or make replacement of parts at points of leakage.

2. Fuel And Combustion Noise (Knock)

Make Reference to Problem 3 and Problem 6.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 13: Loud Valve Train Noise

Probable Cause:

1. Damage To Valve Spring(s)

Make replacement of parts with damage.

2. Damage To Camshaft

Make replacement of parts with damage. Clean engine thoroughly. If replacement of camshaft is made, new valve lifters are also necessary.

3. Damage To Valve Lifter

Clean engine thoroughly. Make replacement of the damaged valve lifters. Inspect camshaft lobes for damage. Look for valves that do not move freely. Make an adjustment to valve lash according to the Subject, Valve Lash Setting.

4. Damage In Bridge For Valves

Make replacement of the bridge and make an adjustment as necessary.

Problem 14: Too Much Valve Lash

Probable Cause:

1. Not Enough Lubrication

Check lubrication in valve compartment. There must be a strong flow of oil at engine high rpm, but only a small flow at low rpm. Oil passages must be clean, especially those that send oil to the cylinder head.

2. Rocker Arm Worn At Face That Makes Contact With Bridge

If there is too much wear, install new parts or rocker arms. Make adjustment of valve lash according to the Subject, Valve Lash Setting.

3. End Of Valve Stem Worn

If there is too much wear, install new valves. Make adjustment to valve lash according to the Subject, Valve Lash Setting.

4. Bridge For Valves Worn

Make an adjustment or replacement as necessary.

5. Worn Push Rods

If there is too much wear, install new push rods. Make adjustment of valve lash according to the Subject, Valve Lash Setting.

6. Broken Or Worn Valve Lifters

Install new valve lifters. Check camshaft for wear. Check for free movement of valves or bent valve stem. Clean engine thoroughly. Make adjustment of valve lash according to the Subject, Valve Lash Setting.

7. Worn Cams On Camshaft

Install a new camshaft. Install new valve lifters. Check for free movement of valves or bent valve stems. Make adjustment of valve lash according to the Subject, Valve Lash Setting.

Problem 15: Valve Rotocoil Or Spring Lock Is Free

Probable Cause:

1. Broken Locks

Broken locks can cause the valve to get into the cylinder. This will cause much damage.

2. Broken Valve Spring(s)

Install new valve spring(s).

3. Broken Valve

Replace valve and other damaged parts.

Problem 16: Oil At The Exhaust

Probable Cause:

1. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

2. Worn Valve Guides

Reconditioning of the cylinder head is needed.

3. Worn Piston Rings

Inspect and install new parts as needed.

Problem 17: Little Or No Valve Lash

Probable Cause:

1. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed. Make adjustment of valve lash according to the Subject, Valve Lash Setting.

Problem 18: Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil

Remove dirty lubrication oil. Install a new oil filter element. Put clean oil in the engine.

2. Air Inlet Leaks

Inspect all gaskets and connections. Make repairs if leaks are found.

3. Fuel Leakage Into Lubrication Oil

This will cause high fuel consumption and low engine oil pressure. Make repairs if leaks are found. Install new parts where needed.

Problem 19: Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Engine Oil Cooler Core

Install a new engine oil cooler. Drain crankcase and refill with clean lubricant. Install new oil filter element.

2. Failure Of Cylinder Head Gasket Or Water Seals

Install a new cylinder head gasket and new water seals in the spacer plate. Tighten the bolts that hold the cylinder head according to the Specifications.

3. Crack Or Defect In Cylinder Head

Install a new cylinder head.

4. Crack Or Defect In Cylinder Block

Install a new cylinder block.

5. Damaged Seals For Cylinder Liners

Make replacement of the seals.

Problem 20: Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion

Check air cleaner for restrictions.

2. Defect in Fuel Injection Nozzle(s)

Install new fuel injection nozzle(s).

3. Wrong Fuel Injection Timing

Make adjustment of timing.

4. Defect In Fuel Ratio Control

Make adjustment to or install new control.

Problem 21: Too Much White Or Blue Smoke

Probable Cause:

1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Engine Misfires Or Runs Rough

Make reference to Problem 3.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Worn Valve Guides

Reconditioning of cylinder head is needed.

5. Worn Piston Rings

Install new parts as necessary.

6. Failure Of Turbocharger Oil Seal

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 22: Engine Has Low Oil Pressure

Probable Cause:

1. Dirty Oil Filter Or Oil Cooler

Install new oil filter. Clean or install new engine oil cooler. Remove dirty oil from engine. Put clean oil in engine.

2. Diesel Fuel In Lubrication Oil

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove the lubrication oil that has diesel fuel in it. Install a new oil filter element. Put clean oil in the engine.

3. Too Much Clearance Between Rocker Arm Shaft And Rocker Arms

Check lubrication in valve compartment. Install new parts as necessary.

4. Oil Pump Suction Pipe Has A Defect

Replacement of pipe is needed.

5. Pressure Regulating Valve Does Not Close

Clean valve and housing. Install new parts as necessary.

6. Oil Pump Is Worn Or Has A Defect

Repair or make replacement of necessary parts.

7. Too Much Clearance Between Crankshaft And Crankshaft Bearings

Check the oil filter for correct operation. Install new parts as necessary.

8. Defect In Oil Pressure Indicator

Install new indicator.

9. Too Much Bearing Clearance For Idler Gear

Inspect bearings and make replacement as necessary.

Problem 23: Engine Uses Too Much Lubrication Oil

Probable Cause:

1. Too Much Lubrication Oil In Engine

Remove extra oil. Find where extra oil comes from. Put correct amount of oil in engine.

2. Oil Leaks

Find all oil leaks. Make repairs as needed.

3. Oil Temperature Is Too High

Check operation of engine oil cooler. Install new parts if necessary. Clean the core of the engine oil cooler.

4. Too Much Oil In The Valve Compartment

Look at both ends of the rocker arm shaft. Be sure a plug is in each end of the shaft.

5. Worn Valve Guides

Reconditioning of the cylinder head is needed.

6. Worn Piston Rings And Cylinder Liners

Inspect and install new parts as needed. Reconditioning of the cylinder block can be necessary.

7. Failure Of Seal Rings In Turbocharger

Check inlet manifold for oil and make repair to turbocharger if necessary.

Problem 24: Engine Coolant Is Too Hot

Probable Cause:

1. Restriction To Flow of Coolant Through Radiator Core Tubes Or Heat Exchanger

Clean and flush radiator or heat exchanger.

2. Restriction To Air Flow Through Radiator

Remove all restrictions of air flow.

3. Low Fan Speed

Check for worn or loose fan belt.

4. Not Enough Coolant In System

Add coolant to cooling system.

5. Pressure Cap Has A Defect

Check operation of pressure cap. Install a new pressure cap if necessary.

6. Combustion Gases In Coolant

Find out where gases get into the cooling system. Make repairs as needed.

7. Water Temperature Regulator (Thermostat) Or Temperature Indicator Has A Defect

Check water temperature regulator for correct operation. Check temperature indicator operation. Install new parts as necessary.

8. Water Pump Has A Defect

Make repairs or replacement of the water pump as necessary. Put correct tension on drive belt for water pump.

9. Too Much Load On The System

Make a reduction to the load.

10. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 25: Exhaust Temperature Is Too High

Probable Cause:

1. Air Inlet Or Exhaust System Has A Restriction

Remove restriction.

2. Wrong Fuel Injection Timing

Make an adjustment to the timing.

Problem 26: Starting Motor Does Not Turn

Probable Cause:

1. Battery Has Low Output

Check condition of battery. Charge battery or make replacement as necessary.

2. Wires or Switch Has Defect

Make repairs or replacement as necessary.

3. Starting Motor Solenoid Has A Defect

Install a new solenoid.

4. Starting Motor Has A Defect

Make repair or replacement of starting motor.

Problem 27:. Alternator Gives No Charge

Probable Cause:

1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defect.

3. Brushes Have A Defect

Install new brushes.

4. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 28: Alternator Charge Rate Is Low Or Not Regular

Probable Cause:

1. Loose Drive Belt For Alternator

Make an adjustment to put the correct tension on the drive belt.

2. Charging Or Ground Return Circuit Or Battery Connections Have A Defect

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts with defects.

3. Alternator Regulator Has A Defect

Install a new alternator regulator.

4. Alternator Brushes Have A Defect

Install new brushes.

5. Rectifier Diodes Have A Defect

Make replacement of rectifier diode that has a defect.

6. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 29: Alternator Charge Is Too High

Probable Cause:

1. Alternator Or Alternator Regulator Has Loose Connections

Tighten all connections to alternator or alternator regulator.

2. Alternator Regulator Has A Defect

Install a new alternator regulator.

Problem 30: Alternator Has Noise

Probable Cause:

1. Drive Belt For Alternator Is Worn Or Has A Defect

Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley

Check groove in pulley for key that holds pulley in place. If groove is worn, install a new pulley. Tighten pulley nut according to Specifications.

3. Drive Belt And Drive Pulley For Alternator Are Not In Alignment

Make an adjustment to put drive belt and drive pulley in correct alignment.

4. Worn Alternator Bearings

Install new bearings in the alternator.

5. Rotor Shaft Is Bent

Make replacement of the rotor shaft.

6. Rectifiers In The Alternator Are Shorted

Make replacement of the diode assembly.

Problem 31: Rack Solenoid Does Not Stop Engine

Probable Cause:

1. Electrical Connections Are Not Correct

Correct electrical connections and wiring.

2. Adjustment For Plunger Shaft Is Not Correct

Make an adjustment to the plunger shaft.

3. Wrong Plunger In Solenoid

Install the correct plunger in the solenoid.

4. Not Enough Plunger Travel

Make an adjustment to the plunger shaft or make replacement of the solenoid if necessary.

5. Defect In Solenoid Wiring

Make replacement of the solenoid.

Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system. Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective fuel injector, but it can also be caused by one or more of the reasons that follow:

a. Not enough air for good combustion.

b. An overload at high altitude.

c. Oil leakage into combustion chamber.

d. Not enough compression.

e. Fuel injection timing incorrect.

Fuel System Inspection

A problem with the components that send fuel to the engine can cause low fuel pressure. This can decrease engine performance.

1. Check the fuel level in the fuel tank. Look at the cap for the fuel tank to make sure the vent is not filled with dirt.

2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a defective bend. Verify that the fuel return line has not collapsed in the sections subject to heat.

3. Install a new fuel filter. Clean the primary fuel filter.

4. To remove air from the fuel system, use the procedure that follows:

a. Use the priming pump to remove air from the low pressure side of the fuel system.

b. Loosen one-half turn the fuel injection line nuts at each adapter in the valve cover base. Move throttle lever to Low Idle position. Use the starting motor to turn the engine until fuel without air flows from the loose connections. Tighten the nuts.

NOTE: Because of the check assemblies in the injection pump outlets the priming pump will not give enough pressure to remove air from the fuel injection lines.

5. Inspect the fuel bypass valve to see that there is no restriction to good operation.

Fuel Transfer Pump

With the engine operating at full load speed, the fuel transfer pump moves fuel through the secondary filter and the fuel injection pump housing at approximately 240 kPa (35 psi).

To check the fuel transfer pump pressure, disconnect the fuel line (from the filter) at the fuel injection pump housing inlet. Install a tee at the inlet and connect the fuel line to the tee. Connect a pressure indicator to the tee and start the engine.

Minimum fuel pressures must be 70 kPa (10 psi) at low idle and 170 kPa (25 psi) at full load speed (and engine under full load).

If the fuel pressure is not above the minimum specifications, stop the engine. Make a replacement of the primary and secondary fuel filters and check to make sure the fuel lines and hoses are not plugged or damaged.

Start the engine and again check the fuel pressure. If the fuel pressure is not above the minimum specification, a repair or replacement of the fuel transfer pump is needed.

Checking Engine Cylinders Separately

An easy check can be made to find the cylinder that runs rough (misfires) and causes black smoke to come out of the exhaust pipe.

Run the engine at the speed that is the roughest. Loosen the fuel line nut at a fuel injection pump. This will stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten each fuel line nut after the test, before the next fuel line nut is loosened. Check each cylinder by this method. When a cylinder is found where the loosened fuel line nut does not make a difference in engine performance, test the injection pump and fuel injection nozzle for that cylinder.

Temperature of an exhaust manifold port, when the engine runs at low idle speed, can also be an indication of the condition of a fuel injection nozzle. Low temperature at an exhaust manifold port is an indication of no fuel to the cylinder. This can possibly be an indication of an fuel injection nozzle with a defect. Extra high temperature at an exhaust manifold port can be an indication of too much fuel to the cylinder, also caused by an fuel injection nozzle with a defect.

The most common defects found with the fuel injection nozzle are:

1. Carbon on tip of the nozzle or in the nozzle orifice.

2. Orifice wear.

3. Dirty nozzle screen.

Testing Fuel Injection Nozzles

Testing of the fuel injection nozzles must be done off the engine. Perform the following tests using the 5P4150 Nozzle Testing Group to determine if nozzle performance is acceptable:

Valve Opening Pressure Test

Flush The Nozzle

Tip Leakage Test

Orifice Restriction Test

Bleed Screw Leakage Test

Refer to Special Instruction SEHS7292, for operation of the 5P4150 Nozzle Testing Group.

Fuel Injection Lines

Fuel Injections Lines With Support Bracket
(1) A vertical line through the number one injection pump.

The nuts that hold a fuel injection line to an injection pump must be tightened to the correct torque. If the nut is loose, fuel will leak from the connection. If the nut is tightened too tight, the inside diameter of the line will become smaller and cause a restriction to the flow of fuel in the line. Use a torque wrench and a 5P0144 Fuel Line Socket to tighten the fuel injection line nuts to 42 ± 7 N·m (30 ± 5 lb ft)

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Be sure the fuel injection line clamps are installed in the correct location. Incorrectly installed clamps may allow the fuel injection lines to vibrate and become damaged. The damaged lines may leak and cause a fire.

Tighten metal-to-metal clamps to a torque of ... 2.3 N·m (20 lb in)

NOTE: The 6V4980 Torque Screwdriver Tool Group is available for applying the correct torque.

Checking The Plunger And Lifter Of An Injection Pump

NOTE: There are no different size spacers available to adjust the timing dimension of the fuel injection pumps. If the pump plunger or the lifter is worn, they must be replaced. Because there is no adjustment to the timing dimension possible, there is No Off Engine Lifter Setting Procedure.

When there is too much wear on the fuel injection pump plunger, the lifter may also be worn and there will not be good contact between the two parts. To stop fast wear on the end of a new plunger, install new lifters in the place of the lifters that have wear.

Wear Between Lifter And Plunger
Figure A illustrates the contact surfaces of a new pump plunger and new lifter. In Figure B the pump plunger and lifter have worn considerably. Figure C shows how the flat end of a new plunger makes poor contact with a worn lifter, resulting in rapid wear to both parts.

An injection pump can have a good fuel flow coming from it but not be a good pump because of slow timing that is caused by wear on the bottom end of the plunger. When making a test on a pump that has been used for a long time, use a micrometer and measure the length of the plunger. If the length of the plunger is shorter than the minimum length (worn) dimension given in the chart install a new pump.

Look for wear at the top part of the plunger. Check the operation of the plunger according to the instructions for the Fuel Injection Test Bench.

Removal And Installation Of Fuel Injection Pumps

This procedure can be done with the fuel injection pump housing on or off the engine.

Before the 6V7050 Compressor Group is used for the first time, or if the group has been disassembled, make the following adjustment:

1. An injection pump that is to be used for this adjustment (or one that is to be removed or installed) must have another injection pump installed next to it. The second injection pump serves as the compressor mounting stud. If there are not two injection pumps next to each other, install two injection pumps without the lifter springs. See Installation Of Fuel Injection Pumps for the correct alignment of the pump at assembly.

Adjustment of 6V7050 Compressor Group
(A) 6V7015 Clamp. (B) Bracket assembly. (C) 4B2046 Nut. (D) 8T0937 Nut. (E) 2N3476 Screw.

2. Put bracket assembly (B) over one of the pump bonnets.

3. Put the clamp ram on the center of the other injection pump bonnet with screw (E) in contact with the fuel line seat.

NOTE: The 6V7015 Clamp (A) should not be locked down.

4. Install and tighten nut (D).

5. Adjust screw in or out until the top of bracket assembly (B) just starts to move when the clamp ram is locked down.

6. Tighten nut (C) to hold screw (E) in position.

Removal Of Fuel Injection Pumps

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NOTICE
Before any parts are removed from the fuel injection pump housing, thoroughly clean all dirt from the housing. Dirt that gets inside the pump housing will cause much damage.

NOTE: The fuel rack must be in the zero (center) position before the fuel injection pumps can be removed or installed. Follow Steps 1 through 5.

Fuel Injection Pump Housing
(1) Plug (rack centering pin). (2) Cover (rack position indicator).

1. Remove plug (1) and cover (2) from the fuel injection pump housing.

Fuel Rack Against Timing Pin in the Zero Position
(3) 6V4186 Timing Pin.

2. Install the 6V4186 Timing Pin (3) in the top of the fuel injection pump housing. Make sure timing pin (3) engages in the slot of the fuel rack as shown.

Holding Fuel Rack in Zero Position
(3) 6V4186 Timing Pin. (4) 8T9198 Bracket Assembly. (5) 1U5426 Compressor Assembly.

3. Install bracket assembly (4) on the fuel injection pump housing. Make sure the lever of the bracket assembly is engaged in the slot of the fuel rack.

4. Install the 1U5426 Compressor Assembly (5) all the way into the 8T9198 Bracket Assembly (4) to compress the spring.

5. Tighten the collet on bracket assembly (4) to hold compressor assembly (5). Spring force now holds the fuel rack against timing pin (3) in the zero position.

Fuel Injection Pump Housing
(3) 6V4186 Timing Pin. (6) 8T5287 Wrench. (7) 6V7050 Compressor Group. (8) Retainer bushing.

6. Remove the fuel injection line from the pump to be removed and also the fuel injection lines on each side of the pump to be removed.

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There is spring force on the fuel injection pump plunger and barrel assembly. Removal of retainer bushing (8) without the 6V7050 Compressor Group correctly installed can cause bodily injury.

7. Use 8T5287 Wrench (6) to loosen bushing (8) one quarter turn. Do not remove the bushing at this time.

8. Install 6V7050 Compressor Group (7) on the pump housing over 8T5287 Wrench (6). Lower the screw in the compressor ram to the fuel line seat before the nut is tightened to hold the compressor group in position. This centers the compressor group.

Fuel Injection Pump Housing
(3) 6V4186 Timing Pin. (6) 8T5287 Wrench. (7) 6V7050 Compressor Group. (8) Retainer bushing.

9. Use 8T5287 Wrench (6) to loosen retainer bushing (8) until it is out of the threads. Slowly raise the compressor tool handle to release the spring force.

Fuel Injection Pump Housing
(9) 8S2244 Extractor.

10. Remove the 6V7050 Compressor Group and the 8T5287 Wrench. Install 8S2244 Extractor (9) on the injection pump threads. Carefully pull the pump straight up and out of the pump housing bore. Remove the spacer from the pump housing bore.

Be careful when an injection pump is disassembled. Do not damage the surface on the plunger. The plunger and barrel are made as a set. Do not put the plunger of one pump in the barrel of another pump. If one part is worn, install a complete new pump assembly. Be careful when the plunger is put into the bore of the barrel. When injection pumps are removed from the fuel injection pump housing, keep the parts together so they can be installed in the same location in the housing.

Installation Of Fuel Injection Pump

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NOTICE
The fuel rack Must Be In The Center Position before the correct installation of an injection pump is possible.

1. Put the fuel rack in the center position. See Removal of Fuel Injection Pumps for this procedure.

Fuel Injection Pump Installation
(1) 8S2244 Extractor. (2) Pump barrel. (3) Gear segment.

2. Put 8S2244 Extractor (1) on the threads of the fuel injection pump.

3. Make sure the lifter for the pump to be installed is at the bottom of its travel (cam lobe is at its lowest point).

4. Put the groove in pump barrel (2) in alignment with the slot (groove) in gear segment (3).

5. Be sure the spacer is in position in the pump housing bore.

Fuel Injection Pump Housing (Top View)
(4) Pin. (5) Dowel.

6. Carefully install the pump straight down into the pump housing bore.

NOTE: The slot (groove) in gear segment (3) must be in alignment with pin (4) in the side of the lifter and the groove in pump barrel (2) must be in alignment with dowel (5) in the housing bore.

Fuel Injection Pump Housing
(6) 6V4186 Timing Pin. (7) 8T5287 Wrench. (8) 6V7050 Compressor Group. (9) Retainer bushing.

7. Remove the 8S2244 Extractor. Put the O-ring seal, retainer bushing (9) and 8T5287 Wrench (7) in position on the top of the injection pump. Install 6V7050 Compressor Group (8).

8. Slowly move the handle of the 6V7050 Compressor Group down to push the injection pump into the bore.

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NOTICE
The handle of the 6V7050 Compressor Group must move smoothly down to the lock position. Do not force the handle if it stops. If the handle does not move smoothly down to the lock position, raise the handle, remove the 6V7050 Compressor Group, and repeat Steps 3 through 8.

9. Put the O-ring seal in position in the pump housing bore. Use the 8T5287 Wrench to install the retainer bushing.

10. Remove the 6V7050 Compressor Group. Tighten the retainer bushing to 230 ± 15 N·m (170 ± 11 lb ft).

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NOTICE
The bushing must be tightened to the correct torque. Damage to the housing will be the result if the bushing is too tight. If the bushing is not tight enough, the pump will have leakage.

11. Install the fuel injection lines to the pump and tighten to 42 ± 7 N·m (30 ± 5 lb ft). See Fuel Injection Lines in this section for more information.

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Be sure the fuel injection line clamps are installed in the correct locations. Incorrectly installed clamps may allow the fuel injection lines to vibrate and become damaged. The damaged lines may leak and cause a fire.

The following steps can be used to insure correct installation and operation of any number of individual replacement pumps on most engines.

12. Remove or activate the shutoff solenoid if it is installed in the rack actuator housing.

NOTE: The manual shutoff override lever can be used to move the shutoff solenoid out of the way so the fuel rack can be moved.

NOTE: To check the installation of a replacement pump, it is necessary to have full rack travel in both directions. The actual zero location of the timing pin and rack are not used to check the installation of replacement pumps.

Check Fuel Rack Travel
(6) 6V4186 Timing Pin. (10) 8T9198 Bracket Assembly.

13. Remove the compressor and bracket assembly (10) from the fuel injection pump housing.

Illustration 1. Correct installation in full load position.

14. Raise the timing pin and move the rack to the full load position. Use finger pressure to be sure the rack is at full rack travel (beyond full load position).

15. If the fuel injection pump installation is correct, when the timing pin is lowered it will be on the rack as shown in Illustration 1.

Illustration 2. Incorrect installation, full load position restricted by less than full rack travel.

16. If the fuel injection pump installation is not correct, the timing pin position will be approximately 1.91 mm (.075 in) toward the slot for each tooth position out of alignment (see Illustration 2). This will reduce fuel rack travel, even though it may not affect the rack setting, because of additional rack travel at static conditions.

Illustration 3. Correct installation at no load (fuel off) position.

17. Raise the timing pin and move the rack to the no load (fuel off) position.

18. If the fuel injection pump installation is correct, when the timing pin is lowered it will be in the timing slot, less than 1.91 mm (.075 in) from the rear face of the slot as shown in Illustration 3.

Illustration 4. Incorrect installation, fuel shutoff position restricted by less than full rack travel.

19. If the fuel injection pump installation is not correct, the timing pin position will be more than 1.91 mm (.075 in) from the rear face of the timing slot in the rack (see Illustration 4).

20. When all fuel injection replacement pumps are installed correctly remove 6V4186 Timing Pin (6) from the fuel injection pump housing and install the plug.

21. Install the gasket and cover over the fuel rack on the side of the fuel injection pump housing.

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NOTICE
If one or more of the fuel injection pumps have been installed wrong, it is possible for the engine to run out of control when started. When any of the fuel injection pumps have been removed and installed with the fuel injection pump housing on the engine, take the precautions (steps) that follow to stop the engine if it starts to overspeed (run out of control).

Turbocharger Air Inlet Opening

a. Remove the air cleaner pipe from the turbocharger leaving the air inlet open as shown.

b. Set the governor control at low idle.

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Be careful when plate is put against air inlet opening. Due to excessive suction, the plate can be pulled quickly against air inlet opening. To avoid crushed fingers, do not put fingers between plate and air inlet opening.

c. Start the engine, and if engine starts to overspeed (run out of control), put a steel plate over the air inlet as shown to stop the engine.

Stopping The Engine

Finding Top Center Compression Position For No. 1 Piston

No. 1 piston at top center (TC) on the compression stroke is the starting point of all timing procedures.

NOTE: On some engines there are two threaded holes in the flywheel. These holes are in alignment with the holes with plugs in the left and right front of the flywheel housing. The two holes in the flywheel are at a different distance from the center of the flywheel so the timing bolt cannot be put in the wrong hole.

Locating Top Center (Left Side of Engine)
(1) Timing bolt. (2) Timing bolt location. (3) Storage location.

1. The timing bolt (1) is kept in storage at location (3) and can be installed in either the left side of the engine at location (2) or in the right side of the engine at location (4). Remove bolts and cover from flywheel housing. Remove the plug from the timing hole in the flywheel housing.

Locating Top Center (Right Side of Engine)
(4) Timing bolt location.

2. Put timing bolt (1) [long bolt that holds cover on the flywheel housing] through the timing hole in the flywheel housing. Use the 9S9082 Engine Turning Tool and 1/2 inch drive ratchet wrench to turn the engine flywheel in the direction of normal engine rotation until the timing bolt engages with the threaded hole in the flywheel.

Using 9S9082 Engine Turning Tool
(1) Timing bolt. (5) 9S9082 Engine Turning Tool.

NOTE: If the flywheel was not turned in the direction of normal engine rotation, or was turned past the timing hole, turn the flywheel clockwise (opposite the direction of the normal engine rotation) approximately 45 degrees. The reason for this step is to be sure the play is removed from the timing gears when the engine is put on top center.

3. Remove the front valve cover from the engine.

Checking No. 1 Inlet And Exhaust Valves

4. The inlet and exhaust valves for the No. 1 cylinder are closed if No. 1 piston is on the compression stroke and the rocker arms can be moved by hand. If the rocker arms can not be moved and the valves are slightly open the flywheel must be turned again. Remove the timing bolt and turn the flywheel in the direction of normal engine rotation 360 degrees until the timing bolt can be installed. The No. 1 piston is now in the top center compression position.

Checking Engine Timing With 8T5300 Timing Indicator Group And 8T5301 Diesel Timing Adapter Group

8T5300 Timing Indicator Group
(1) 8T5250 Engine Timing Indicator. (2) 5P7366 Cable Assembly. (3) 6V2197 Magnetic Transducer. (4) 5P7362 Cable. (5) 6V2199 and 6V3093 Transducer Adapters. (6) 8K4644 Fuse.

The 8T5300 Timing Indicator Group must be used with the 8T5301 Diesel Timing Adapter Group.

8T5301 Diesel Timing Adapter Group
(7) 5P7437 Adapter. (8) 6V2198 Cable. (9) 5P7436 Adapter. (10) 6V7910 Transducer. (11) 5P7435 Adapter. (12) 6V3016 Washer.

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A high pressure fuel line must be disconnected. To avoid personal injury or fire from fuel spray, the engine must be stopped before the fuel line is disconnected.

When checking the dynamic timing on an engine without a mechanical advance, Caterpillar recommends that the service personnel calculate and graph the dynamic timing on a worksheet like SEHS8140. These worksheets are available in pads of 50 sheets, order one SEHS8140. See Special Instruction SEHS8580, for information required to calculate the timing curve.

After the timing values are calculated and plotted, the dynamic timing should be checked with the 8T5300 Engine Timing Indicator Group. To do this, the service personnel must operate the engine from 1000 rpm (base rpm) to high idle and from high idle to 1000 rpm (base rpm). Unstable readings are often obtained below 1000 rpm. They must record the dynamic timing at each 100 rpm and at the specified speeds during both acceleration and deceleration. Then they should plot the results on the worksheet.

Inspection of the plotted value will show if the timing is within specifications. See Special Instruction SEHS8580 for information required to calculate the timing.

1. See the Engine Information Plate for the performance specification number and make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct timing specifications to use.

2. Make reference to Operation Instructions inside the lid of the 8T5300 Timing Indicator (1) or Special Instruction SEHS8580 for complete instructions and calibration.

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The engine must be stopped before the timing indicator group is installed. A high pressure fuel line must be disconnected and a probe must be installed against the flywheel.

Transducer In Position (Typical Example)
(10) Injection transducer. (13) Fuel injection line for No. 6 cylinder.

3. Loosen all fuel line clamps that hold No. 6 fuel injection line, and disconnect fuel injection line (13) for the No. 6 cylinder at the fuel injection pump. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn adapter (9) onto the fuel pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in the adapter.

4. Put the 5P7435 Tee Adapter (11) on the injection transducer (10), and put the end of the 5P7435 Tee Adapter (11) in the "window" of the 5P7436 Adapter (9).

5. Put fuel injection line (13) on top of 5P7435 Tee Adapter (11). Install 5P7437 Adapter (7), and tighten to 40 N·m (30 lb ft).

6. Remove the plug from the flywheel housing. Install transducer adapter (5) into the hole the plug was removed from. Tighten only a small amount.

Transducer In Position
(3) Magnetic transducer. (5) Transducer adapter.

7. Push magnetic transducer (3) into the transducer adapter (5) until it makes contact with the flywheel. Pull it back out 1.5 mm (.06 in) and lightly tighten the knurled locknut.

8. Connect the cables from the transducers to Engine Timing Indicator (1). Calibrate and make adjustments. For calibration procedure, make reference to Special Instruction SEHS8580.

9. Start the engine, and let it reach operating temperature. Then run the engine at approximately one-half throttle for eight to ten minutes before measuring timing.

10. Run the engine at the speeds required, and record the timing indicator readings. If the engine timing is not correct, make reference to Checking Engine Timing By Timing Pin Method for static adjustment of the fuel injection pump drive.

Checking Engine Timing By Timing Pin Method

1. Put No. 1 piston at top center on the compression stroke. Make reference to Finding Top Center Compression Position For No. 1 Piston. Remove the timing bolt from the flywheel and use 9S9082 Engine Turning Tool to rotate the crankshaft clockwise 45 degrees as viewed from the flywheel end of the engine.

Fuel Injection Pump
(1) Plug (timing pin hole).

2. Remove plug (1) from the fuel injection pump housing.

Timing Pin Installed
(2) 6V4186 Timing Pin.

3. Install 6V4186 Timing Pin (2) in the fuel injection pump housing as shown. Slowly rotate the crankshaft counterclockwise (as viewed from the flywheel end of the engine) until timing pin (2) goes into the slot in the fuel pump camshaft.

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NOTICE
Too much pressure on the timing pin can damage the fuel injection pump or the timing pin.

4. Put the timing bolt in the timing hole in the flywheel housing. Rotate the crankshaft counterclockwise (as viewed from the flywheel end of the engine) until the fuel pump camshaft is tight against timing pin (2). This removes gear clearance from the drive train. If the bolt can be installed in the timing hole in the flywheel, the timing of the fuel injection is correct.

Front Of Engine
(3) Access cover.

5. If the timing bolt does not go into the timing hole in the flywheel, the timing is not correct. Do the steps that follow to adjust the fuel injection pump timing.

a. Remove access cover (3).

(Governor And Fuel Pump Drive Group).
(3) Access cover. (4) Bolts.

b. Loosen four bolts (4). With timing pin (2) installed and the timing bolt removed, turn the flywheel clockwise (opposite the direction of engine rotation) a minimum of 45 degrees. The reason for this step is to remove play from the timing gears when the engine is put on top center (TC).

c. Tighten two bolts (4) 180 degrees apart, evenly to a torque of 3 N·m (27 lb in). This puts a slight clamping force on the gear for the next step.

d. Turn the flywheel slowly in the direction of engine rotation until the timing bolt can be installed in the flywheel. The number one piston is now at top center (TC).

NOTE: The crankshaft can be turned from the front of the engine by using a wrench on the vibration damper bolts, if necessary.

e. Tighten eight bolts (4) to a torque of 55 ± 10 N·m (40 ± 7 lb ft). Remove the timing bolt from the flywheel and timing pin (2) from the fuel injection pump housing.

6. Turn the flywheel clockwise (opposite the direction of normal engine rotation) a minimum of 45 degrees. Now, turn the flywheel in the direction of engine rotation until timing pin (2) drops into slot of pump camshaft. Now turn the flywheel more, in the direction of normal engine rotation, until all gear clearance is removed from the drive train. Check to see that the timing bolt will go into the flywheel.

7. If the timing is not correct, do the procedure of Steps 5b through 5e again.

8. If the timing is correct, remove the timing bolt from the flywheel and timing pin from the fuel injection pump housing. Install cover (3) and plug (1).

Fuel Setting Procedure

6V6070 Governor Adjusting Tool Group

NOTE: If the 8T1000 Electronic Position Indicator Group is used, make reference to Special Instruction SEHS8623 for information on the use of the tool group.

The fuel setting procedure can be used with the fuel injection pump and governor on or off the engine.

Fuel Injection Pump And Governor
(1) Cover (rack position indicator). (2) Plug (rack centering pin).

1. Remove plug (2) and cover (1) from the fuel injection pump housing.

Indicator And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 6V6109 Bracket Assembly. (5) 2A0762 Bolt (1/4-20 NC × .625 in). (6) 8H9178 Ground Body Bolt (1/4-20 NC × 1.00 in). (7) 5P4814 Collet. (8) 6V6106 Dial Indicator.

NOTE: If the 8T1000 Position Indicator Group is used instead of the dial indicator, use Step 3 for the installation of the probe.

2. Install the rack position indicator as follows:

a. Install the 5P4814 Collet (7) on the 6V6109 Bracket Assembly (4).

Slot In Fuel Injection Pump Rack
(9) Slot.

b. Position the indicator arm in approximately the middle of its travel to make sure that it will engage in slot (9) in the rack. Put 6V6109 Bracket Assembly (4) in position on the fuel injection pump housing.

c. Install 8H9178 Ground Body Bolt (6) first. Then install 2A0762 Bolt (5).

d. Be sure the indicator arm moves freely.

e. Put indicator (8) in position in collet (7).

f. Put the 9S8903 Contact Point on the 6V2030 Extension and install on indicator (8).

NOTE: The 9S8903 Contact Point will not go through the collet and must be assembled after the indicator stem has passed through the collet.

g. Tighten collet (7) just enough to hold the dial indicator.

3. Install the rack position probe as follows:

a. Install the 5P4814 Collet (7) on the 6V6109 Bracket Assembly (4).

b. Position the indicator arm in approximately the middle of its travel to make sure that it will engage in slot (9) in the rack. Put 6V6109 Bracket Assembly (4) in position on the fuel injection pump housing.

c. Install 8H9178 Ground Body Bolt (6) first. Then install 2A0762 Bolt (5).

d. Be sure the indicator arm moves freely.

e. Put probe (A) in position in collet (7).

f. Put the 9S8903 Contact Point on the 6V2030 Extension and install on probe (A).

NOTE: The 9S8903 Contact Point will not go through the collet and must be assembled after the indicator stem has passed through the collet.

g. Adjust probe (A) in collet (7) so that the shaft can be moved through the entire measurement range without reaching the end of the shaft travel. Tighten the collet.

Probe And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 6V6109 Bracket Assembly. (5) 2A0762 Bolt (1/4-20 NC × .625 in). (6) 8H9178 Ground Body Bolt. (1/4-20 NC × 1.00 in). (7) 5P4814 Collet. (A) 8T1002 Probe.

4. Remove the shutoff solenoid, if equipped, or cover and install the 6V6151 Adapter (10).

Position Fuel Injection Pump Rack
(10) 6V6151 Adapter. (11) 6V7942 Hook.

5. Move the governor control lever to the "LOW IDLE" position (rotate governor shaft counterclockwise).

6. Install the 6V4186 Timing Pin (3) in the top of the fuel injection pump housing. Push the timing pin in until contact with the fuel rack is made.

7. Use 6V7942 Hook (11) through 6V6151 Adapter (10) to push the sleeve and rack to the "SHUTOFF" position. Make sure timing pin (3) engages in slot (9).

Push Rack To Shutoff
(11) 6V7942 Hook. (12) Servo valve.

8. Move the governor control lever to the "FULL LOAD" position (rotate governor shaft clockwise) and fasten it in this position.

Pull Rack Against Timing Pin
(11) 6V7942 Hook. (12) Servo valve.

9. Use the 6V7942 Hook (11) to pull the sleeve and rack [through servo valve (12)] against the timing pin.

Fuel Rack Against Timing Pin

10. Adjust the 6V6106 Dial Indicator (8) in the collet to zero and tighten the collet. Make sure all needles of the indicator are on zero.

NOTE: If the Electronic Position Indicator Group is used, press the ZERO switch on the front panel. This sets the display to zero.

11. Remove the 6V4186 Timing Pin (3), 6V7942 Hook and release the governor control lever.

6V7941 Compressor Assembly
(13) Rod.

12. Turn rod (13) in the 6V7941 Compressor Assembly until the knob is approximately 25.4 mm (1.00 in) away from the compressor body.

NOTE: The 6V7941 Compressor Assembly is used to compress the overfueling spring through the linkage. The overfueling spring must be compressed to get an accurate fuel setting measurement.

Install The 6V7941 Compressor Assembly
(10) 6V6151 Adapter. (14) 6V7941 Compressor Assembly.

13. Install compressor assembly (14) in adapter (10) as shown.

Static Fuel Setting
(13) Rod (part of 6V7941 Compressor Assembly). (15) 8T0500 Circuit Tester. (16) Insulated terminal.

14. Fasten the clip end of the 8T0500 Circuit Tester (15) to insulated terminal (16), and put the other end to a good electrical ground.

NOTE: If the Electronic Position Indicator Group is used, the built-in continuity tester can be used instead of 8T0500 Circuit Tester (15). Use the built-in tester only for static readings.

15. Hold the governor control lever in the "FULL LOAD" position (rotate governor shaft clockwise).

16. Turn rod (13) of compressor assembly in (clockwise) until the light in circuit tester (15) goes off and the dial indicator hands move an additional 2 mm in the negative (-) direction after the light goes out (2 complete revolutions of the large needle on the dial indicator).

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NOTICE
DO NOT turn the rod any further in if the rod begins to tighten. Damage to the governor can occur if the rod is turned in further.

NOTE: The static fuel setting (Step 18) and the static full torque setting (Step (19) must be within ± .25 mm of the setting on the Engine Information Plate. If the setting is within ± .25 mm an adjustment is not necessary. If the Engine Information Plate is gone or the Full Torque Setting is not on the Engine Information Plate, see TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct settings.

17. Remove adjustment screw cover (17) from the rear of the governor housing.

18. Slowly turn rod (13) out (counterclockwise) until the circuit tester light just comes on. This is the static fuel setting. See the Engine Information Plate or the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct static fuel setting.

NOTE: When the rod is turned out, there can be a small initial movement of the dial indicator hands, then, they will stop moving while the rod is turned out for approximately another 11/2 turns. Now the indicator hands will begin to move again and will follow the turning of the rod until the setting is reached. It is important that the rod be turned slowly so that the rack can follow the governor components.

NOTE: If rod (13) is turned out too fast, a wrong measurement can be read on the dial indicator as the light comes on. Repeat Steps 16 and 18 to make sure the correct measurement is taken.

19. Continue to turn the rod out until the indicator hand stops moving. Then turn the rod out two additional turns. Push in on the rack stop collar to make sure it is in the correct position. The new reading on the indicator is the full torque static setting.

Example:

Static Fuel Setting = 2.18 mm

Full Torque = 3.18 mm

This means the torque rise setting is 1.00 mm. An addition of the fuel setting and the torque rise setting is not necessary.

20. See the Engine Information Plate for the correct static full torque setting.

21. Determine how much the settings will have to be changed (see examples). Use the chart that follows to determine how far the adjusting screws must be turned.

Adjustment Of Governor
(17) Adjustment screw cover.

Since "desired setting" is higher than "actual reading," turn adjusting screw out (counterclockwise) approximately 1/4 turn. Recheck the new setting and readjust if necessary.

Since "desired setting" is lower than "actual reading," turn the adjusting screw in (clockwise) approximately 11/8 turns. Recheck the new setting and readjust if necessary.

Negative numbers work differently than positive numbers. If one number (-1.25) has a larger digital value than another one (-1.05), the first number (-1.25) is actually less than the other one. Therefore, in this example the "desired setting" is lower than the "actual reading". Turn the adjusting screw in (clockwise) approximately 1/4 turn. Recheck the new setting and readjust if necessary.

The "desired setting" is higher than the "actual reading". Turn the adjusting screw out (counterclockwise) approximately 11/8 turns. Recheck the new setting and readjust if necessary.

The "desired setting" is lower than the "actual reading". Turn the adjusting screw in approximately 27/8 turns.

The "desired setting" is higher than the "actual reading". Turn the adjusting screw out approximately 27/8 turns.

Adjustment Of Fuel Setting
(18) Fuel adjustment screw. (19) 6V2106 Rack Adjustment Tool Group.

Adjustment Of Full Torque Setting
(19) 6V2106 Rack Adjustment Tool Group. (20) Torque rise adjustment screw.

NOTE: If you are working from the side of the engine and cannot see the adjusting screws, use the outer edge of the opening in the governor housing to guide the 6V2106 Tool Group onto the fuel setting screw. Use the inner edge of the opening to guide the 6V2106 Tool Group onto the full torque setting adjustment screw.

22. If both settings are to be increased, turn torque rise adjustment screw (20) out (counterclockwise) the same number of turns as fuel adjustment screw (18) is going to be changed. If the static fuel setting is going to be decreased, it is not necessary to change the full torque setting at this time.

23. Use 6V2106 Rack Adjustment Tool Group (19) to loosen the locknuts for adjustment screws and to turn the adjustment screws.

24. Adjust the fuel setting screw the number of turns determined in Step 21. Always recheck the setting after each adjustment and adjust again if needed.

NOTE: There is a zero tolerance for the fuel setting and full torque setting when an adjustment is made.

25. After the static fuel setting is correct, adjust the torque rise adjustment screw the number of turns determined in Step 21. Always recheck the setting after each adjustment and adjust again if needed.

Fuel Ratio Control And Governor Check

NOTE: The governor seals do not have to be cut or removed for the procedure that follows.

1. Install the rack position indicator to measure fuel rack movement. See Steps 1 and 2 in the Fuel Setting Procedure for the correct installation of the tooling.

2. Turn the engine start key to the ON position to activate the shutoff solenoid. Do not start the engine at this time.

3. Move the governor control linkage to the full FUEL ON position and hold or fasten it in this position.

4. Install the 6V4186 Timing Pin in the rack zeroing hole near the front of the fuel injection pump housing.

5. With the governor control lever in the full FUEL ON position, use a 1N9954 Lever and move the manual shutoff shaft slowly to the FUEL OFF position (counterclockwise). Watch and make sure the timing pin drops and engages with the slot in the fuel rack.

6. Release the manual shutoff shaft and zero the dial indicator. Move the dial indicator in the collet to zero and tighten the collet. Make sure all three needles of the indicator are on zero.

7. Remove the 6V4186 Timing Pin and watch the dial indicator movement. The indicator should show movement in the FUEL ON direction. If no movement occurs repeat Steps 4, 5 and 6 to zero the indicator.

8. Release the governor control shaft and linkage.

Remove Boost Line
(1) Air Line.

9. Remove air line (1) from the engine. Put plugs over the openings to keep dirt out of the system.

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To help prevent an accident caused by parts in rotation, work carefully around an engine that has been started.

10. Start the engine and operate it for a minimum of five minutes to get the governor and engine up to normal operating temperatures.

11. Check the leak down rate of the fuel ratio control (with the engine operating at low idle) as follows:

a. Connect a pressure indicator, a shutoff valve, a pressure regulator and an air supply to fitting.

b. Apply 70 kPa (10 psi) air pressure to the fuel ratio control.

c. Turn the shutoff valve OFF and check the leak down rate. Leakage of 20 kPa (3 psi) in 30 seconds is acceptable.

d. If leakage is more than 20 kPa (3 psi) in 30 seconds, the fuel ratio control must be repaired before Steps 13 and 14 are done.

e. Keep 70 kPa (10 psi) air pressure on the fuel ratio control for Step 12.

NOTE: Step 11 also activates the fuel ratio control for Step 12.

Apply Air Pressure
(2) Fitting. (3) Cover.

12. From low idle, rapidly move the governor control shaft to the full FUEL ON position and read the measurement on the dial indicator. Read the indicator carefully because this reading will be a maximum for only a moment. Make a record of the maximum dial indicator reading. If full measurement is not reached, increase the air pressure to make sure there is full fuel ratio control movement.

NOTE: The fuel ratio control is activated and the maximum dial indicator reading is dynamic full torque setting of the engine. This setting is 0.5 mm (.02 in) greater than the static full torque setting given on the Engine Information Plate or later engines or in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

NOTE: On some CARB approved engines or with fuel ratio controls out of adjustment, the fuel ratio control can activate shortly after engine startup. At this time the dial indicator reading can be the dynamic fuel ratio control setting. Continue the checking procedure to find the dynamic full torque setting at Step 16.

13. Release all air pressure from the fuel ratio control. Start at 900 rpm and rapidly move the governor control shaft to the full FUEL ON position and read the measurement on the dial indicator. Read the dial indicator carefully because this reading will be a maximum for only a moment. Make a record of the maximum dial indicator reading. This is the dynamic fuel ratio control setting for the engine.

14. If the dynamic fuel ratio control setting is within ± 0.25 mm of the specification given on the Engine Information Plate or in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche, an adjustment is not necessary.

15. For adjustment of the control see Fuel Ratio Control Adjustment.

16. Check boost pressure that gives full torque rack travel as follow:

a. Connect a pressure indicator, a pressure regulator and an air supply to fitting (2).

b. Apply 25 kPa (4 psi) air pressure to the fuel ratio control.

c. Start at 900 rpm and rapidly move the governor control shaft to the full FUEL ON position and make a record of the maximum dial indicator reading.

d. Repeat this procedure several times, each time increase the air pressure 5 kPa (.5 psi).

e. Make a record of the first air pressure setting that gives full torque rack travel. Full torque rack travel was measured in Step 12.

f. This is the boost pressure that moves the fuel ratio control out of the rack control position. This pressure gives dynamic full torque rack travel.

Fuel Ratio Control Adjustment

NOTE: These emissions regulated engines are equipped with tamper resistant bolts on the fuel ratio control and cover. Adjustments and repairs should be made by an authorized Caterpillar dealer.

NOTE: Before the governor seals are cut or removed, See Fuel Ratio Control And Governor Check to make sure an adjustment is needed.

1. See the Engine Information Plate or the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for correct dynamic fuel ratio control setting specification before an adjustment is made.

2. Install and zero the rack position indicator group. See Fuel Ratio Control And Governor Check for this procedure.

Remove Boost Line
(1) Air line.

3. Remove air line (1) and cover (3) from the engine.

Remove Cover
(2) Fitting. (3) Cover.

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To help prevent an accident caused by parts in rotation, work carefully around an engine that has been started.

4. Start the engine and operate it for a minimum of five minutes to get the governor and engine up to normal operating temperature.

Adjustment Components.
(4) Valve extension. (5) Nut. (6) Retainer.

5. Hold retainer (6) in position and loosen nut (5). This keeps the fuel ratio control diaphragm from turning when nut (5) is loosened or tightened.

6. Turn valve extension (4) to get the correct setting. A clockwise direction gives a more positive setting. The counterclockwise direction will give a more negative setting. Several adjustments of valve extension (4) may be needed to get the correct dynamic fuel ratio control setting.

7. After each adjustment is made, check the dynamic fuel ratio control setting. Start at 900 rpm and rapidly move the governor control shaft to the full Fuel On position and read the measurement on the dial indicator. Read the dial indicator carefully because this reading will be a maximum for only a moment. Make a record of the maximum dial indicator reading.

NOTE: If the correct dynamic fuel ratio control setting cannot be made with this adjustment, the internal governor linkage must be checked and adjusted or the fuel ratio control needs repair or replacement. See Check And Adjustment Of The Fuel Ratio Control Linkage for the governor linkage procedure.

8. After the correct adjustment has been made, tighten nut (5). Check the dynamic fuel ratio control setting again.

9. Install the gasket and cover (3) on the fuel ratio control. Tighten the bolts to a torque of 9 ± 3 N·m (7 ± 2 lb ft)

10. Apply 70 kPa (10 psi) air pressure to the fuel ratio control at fitting (2). This will fully extend the fuel ratio control to get dynamic full torque.

11. Check the dynamic full torque setting. Start at 900 rpm and rapidly move the governor control shaft to the full Fuel On position and read the maximum measurement on the dial indicator.

NOTE: If the dynamic full torque setting cannot be reached a repair or replacement of the fuel ratio control is needed.

12. Stop the engine.

13. Install the wire and seal on the fuel ratio control.

14. Install air line (1) on the engine.

15. Remove the rack position indicator tooling.

Check And Adjustment Of The Fuel Ratio Control Linkage

6V6070 Governor Adjusting Tool Group

The check and adjustment of the fuel ratio control linkage can be used with the fuel injection pump and governor on or off the engine.

NOTE: Start with Step 13 of this procedure if the governor adjusting tools have already been installed to check the fuel setting.

Fuel Injection Pump And Governor
(1) Cover (rack position indicator). (2) Plug (rack centering pin).

1. Remove plug (2) and cover (1) from the fuel injection pump housing.

Indicator And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 8T9198 Bracket Assembly. (5) 2A0762 Bolt. (6) 8H9178 Ground Body Bolt. (7) 5P4814 Collet. (8) 6V6106 Dial Indicator.

2. Install the rack position indicator as follows:

a. Install the 5P4814 Collet (7) on the 8T9198 Bracket Assembly (4).

Slot In Fuel Injection Pump Rack
(9) Slot.

b. Position the indicator arm in approximately the middle of its travel to make sure that it will engage in slot (9) in the rack. Put 8T9198 Bracket Assembly (4) in position on the fuel injection pump housing.

c. Install 8H9178 Ground Body Bolt (6) first. Then install 2A0762 Bolt (5).

d. Be sure the indicator arm moves freely.

e. Put indicator (8) in position in collet (7).

f. Put the 9S8903 Contact Point on the 6V2030 Extension and install on indicator (8).

NOTE: The 9S8903 Contact Point will not go through the collet and must be assembled after the indicator stem has passed through the collet.

g. Tighten collet (7) just enough to hold the dial indicator.

3. Remove the shutoff solenoid, if equipped, or cover and install the 6V6151 Adapter (10).

Position Fuel Injection Pump Rack
(10) 6V6151 Adapter. (11) 6V7942 Hook.

4. Move the governor control lever to the Low Idle position (rotate governor shaft counterclockwise).

5. Install the 6V4186 Timing Pin (3) in the top of the fuel injection pump housing. Push the timing pin in until contact with the fuel rack is made.

6. Use 6V7942 Hook (11) through 6V6151 Adapter (10) to push the sleeve and rack to the shutoff position. Make sure timing pin (3) engages in slot (9).

Push Rack To Shutoff
(11) 6V7942 Hook. (12) Servo valve.

7. Move the governor control lever to the Full Load position (rotate governor shaft clockwise) and fasten it in this position.

Pull Rack Against Timing Pin
(11) 6V7942 Hook. (12) Servo valve.

8. Use the 6V7942 Hook (11) to pull the sleeve and rack [through servo (12)] against the timing pin.

Fuel Rack Against Timing Pin

9. Adjust the 6V6106 Dial Indicator (8) in the collet to zero and tighten the collet. Make sure all three needles of the dial indicator are on zero.

10. Remove the 6V4186 Timing Pin (3), 6V7942 Hook and release the governor lever.

6V7941 Compressor Assembly
(13) Rod.

11. Turn rod (13) in the 6V7941 Compressor Assembly until the knob is approximately 25.4 mm (1.00 in) away from the compressor body.

NOTE: The 6V7941 Compressor Assembly is used to remove clearance in the governor linkage to get accurate fuel setting measurements.

Install the 6V7941 Compressor Assembly
(10) 6V6151 Adapter. (14) 6V7941 Compressor Assembly.

12. Install 6V7941 Compressor Assembly (14) in 6V6151 Adapter (10) as shown.

Remove Fuel Ratio Control
(15) Air supply line. (16) Fuel ratio control.

13. Remove air supply line (15) and fuel ratio control (16).

Remove Orifice Screen Assembly
(A) Location for screen assembly.

Fuel Ratio Governor Adjustment Check
(17) 6V2017 Governor Adjusting Tool. (18) 6V2106 Rack Adjusting Tool (outer part).

14. Remove the orifice screen assembly from the governor housing at location (A). This screen must be removed to 6V2017 Governor Adjusting Tool (17) can fit square against the governor housing.

NOTE: If it is thought that it will be necessary to change linkage adjustment, install the outer part of 6V2106 Rack Adjusting Tool (18) along the left side of the governor, before bolts for 6V2017 Governor Adjusting Tool (17) are tightened.

15. Move the governor control lever to the Low Idle position and install 6V2017 Governor Adjusting Tool (17) as shown.

16. Move the governor control lever to Full Load position and hold there.

Checking Fuel Ratio Control Setting
(14) 6V7941 Compressor Assembly.

17. Turn the knob so the rod moves in 6V7941 Compressor Assembly (14) until the needles of the dial indicator move approximately 1 mm (one revolution of the large needle).

18. Slowly turn the knob to move the rod out of 6V7941 Compressor Assembly (14) until the needles of the dial indicator stop movement. This is the Static Fuel Ratio Control Lever Setting.

NOTE: When the rod is turned out, there may be a small initial movement of the dial indicator needles, then they will stop moving while the rod is turned out for approximately 1 1/2 turns more. Now the indicator needles will begin to move again, and will follow the turning of the knob until the setting is reached. It is important that the rod be turned slowly, so that fuel rack can follow the movement of the governor components.

19. See the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct Static Fuel Ratio Control (lever) setting dimension, and compare it to the dial indicator reading. The dial indicator reading must be within ± .25 mm (.010 in) of the dimension given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche or an adjustment is needed.

Tools For Linkage Adjustment
(18) 6V2106 Rack Adjusting Tool (outer part). (19) 6V2104 Hex Wrench.

Location Of Linkage Adjustment
(20) Adjustment screw. (21) Locknut.

20. If an adjustment is necessary, use 6V2106 Rack Adjusting Tool (18) to loosen locknut (21) and then use the 6V2104 Hex Wrench (19) (part of the 6V2106 Rack Adjusting Tool) to turn adjusting screw (20). Turn the screw out [counterclockwise (CCW)] to make the setting more positive, or in [clockwise (CW)] to make the setting more negative. Be sure to tighten the locknut after adjustment is complete. There is a zero tolerance for the linkage setting if an adjustment is made.

NOTE: The needles of the dial indicator will not follow the turning of the adjustment screw. It will be necessary to do Steps 15 through 17 until the adjustment is correct.

Adjustment Of Fuel Ratio Control Linkage

Engine Speed Measurement

6V3121 Multitach Group

The 6V3121 Multitach Group can measure engine speed from a magnetic pickup on the flywheel housing. It also has the ability to measure engine speed from visual engine parts in rotation.

Special Instruction, SEHS7807 is with the 6V3121 Multitach Group and gives instructions for the test procedure.

The 6V4950 Injection Line Speed Pickup Group is another diagnostic tool accessory that can be used with the 6V2100 Multitach. It can be used on all Caterpillar Diesel Engines equipped with 6 mm (.25 in) single wall fuel injection lines. With this pickup group, engine speed can be measured quickly, automatically and with an accuracy of ± 1 rpm.

Special Instruction, SEHS8029 is with the group and gives instructions for use of the 6V4950 Injection Line Speed Pickup Group.

Governor Adjustments

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NOTICE
A mechanic with training in governor adjustments is the only one to make the adjustment to the set point rpm.

Engine rpm must be checked with an accurate tachometer. Make reference to Engine Speed Measurement.

Low Idle Adjustment

NOTE: The correct Low Idle rpm is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche.

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To help prevent an accident caused by parts in rotation, work carefully around an engine that has been started.

Start the engine and run until the temperature of normal operation is reached. Check low idle rpm with no load on the engine. If an adjustment is necessary, use the procedure that follows:

Low Idle Adjustment
(1) Low idle stop screw.

1. To adjust the Low Idle rpm, start the engine and run with the governor control lever in the low idle position. Loosen the locknut for low idle stop screw (1). Turn the low idle screw to get the correct low idle rpm. Increase engine speed and return to low idle and check low idle speed again. Tighten the locknut.

Checking Set Point (Balance Point)

The engine set point is an adjusted specification and is important to the correct operation of the engine. High idle rpm is NOT an adjusted specification. Set point (formerly balance point) is full load rpm plus an additional 20 rpm. Set point is the rpm at which the fuel setting adjustment screw and stop or first torque spring just start to make contact. At this rpm, the fuel setting adjustment screw and stop or first torque spring still have movement between them. When additional load is put on the engine, the fuel setting adjustment screw and stop or first torque spring will become stable against each other. Set point is controlled by the fuel setting and the high idle adjustment screw.

There is a new and more accurate method for checking the "set point", formerly called the balance point, of the engine. If the tools for the new method are not available, there is an alternate method for checking the "set point".

The 6V4060 Engine Set Point Indicator Group with the 6V2100 Multitach can be used to check the set point. Special Instruction SEHS7931 gives instructions for installation and use of this tool group.

6V4060 Engine Set Point Indicator Group

Alternate Method

NOTE: Do not use the machine tachometer unless its accuracy is know to be within ± 1 rpm.

If the set point is correct and the high idle speed is within specifications, the fuel system operation of the engine is correct. The set point for the engine is:

A. At 20 rpm greater than full load speed.

B. The rpm where the fuel setting adjustment screw stop or first torque spring just make contact.

Use the procedure that follows to check the set point. Make reference to Techniques For Loading Engines in Special Instruction SEHS7050.

1. Connect a tachometer which has good accuracy to the tachometer drive.

Terminal Location
(2) Brass terminal screw.

2. Connect the clip end of the 8T0500 Circuit Tester to the brass terminal screw (2) on the governor housing. Connect the other end of the tester to a place on the fuel system which is a good ground connection.

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Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

3. Start the engine.

4. With the engine at normal conditions for operation, run the engine at high idle.

5. Make a record of the speed of the engine at high idle.

6. Add load on the engine slowly until the circuit tester light just comes on (minimum light output). This is the set point.

7. Make a record of the speed (rpm) at the set point.

8. Repeat Step 6 several times to make sure that the reading is correct.

9. Stop the engine. Make a comparison of the records from Steps 6 and 7 with Full Load Speed from the Engine Information Plate. If the Engine Information Plate is not available, see the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. The tolerance for the set point is ± 10 rpm. The tolerance for the high idle rpm is ± 50 rpm in chassis and ± 30 rpm on a bare engine. If the readings from Steps 5 and 7 are within the tolerance, no adjustment is needed.

NOTE: Engines will have the actual Dyno High Idle stamped on the Engine Information Plate. It is possible, in some applications that the high idle rpm will be less than the actual lower limit. This can be caused by high parasitic loads such as hydraulic pumps, compressors, etc.

Adjusting Set Point (Balance Point)

1. If the set point and the high idle rpm are within tolerance, no adjustment is to be made.

2. If the set point rpm is not correct, remove cover (3).

Remove Cover
(3) Cover.

Set Point Adjustment
(4) Locknut. (5) Adjustment screw.

3. Loosen locknut (4) and turn adjustment screw (5) to adjust the set point to the midpoint of the tolerance.

4. When the set point is correct, check the high idle rpm. The high idle rpm must not be more than the high limit of the tolerance.

If the high idle rpm is more than the high limit of the tolerance, check the governor spring and flyweights. If the high idle rpm is less than the low limit of the tolerance, check for excess parasitic loads and then the governor spring and flyweights.

Dashpot Adjustment

Adjustment Of Dashpot
(1) Needle Valve.

This adjustment controls the amount of restriction to oil flow into and out of the dashpot chamber. Too much oil flow will cause the governor to hunt, and too little oil flow will cause a slow governor action.

1. Turn needle valve (1) in (clockwise) until it stops. Now, open needle valve (1) two full turns (counterclockwise). The exact point of adjustment is where the governor gives the best performance.

NOTE: Do not keep needle valve (1) fully closed. This can cause excessive overshoot on start up or load rejection.

2. Check governor operation.

With the engine running at medium (mid) speed, load the engine (at least one-quarter load) to find the stability of the setting. Quickly remove the load. A slight overshoot of speed is desired, as it reduces response time. The engine speed should return to smooth steady operation. If it does not have a slight overshoot and return to a smooth steady operation, adjust the needle valve and repeat the above procedure.

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

There will be a reduction of horsepower and efficiency of the engine if there is a restriction in the air inlet or exhaust system.

Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that has gone through air cleaner) of more than 6.23 kPa (25 inches of H₂O).

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 9.96 kPa (40 inches of H₂O).

Measurement Of Pressure In Inlet Manifold

The efficiency of an engine can be checked by making a comparison of the pressure in the inlet manifold with the information given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. This test is used when there is a decrease of horsepower from the engine, yet there is no real sign of a problem with the engine.

The correct pressure for the inlet manifold is given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Development of this information is done with these conditions:

a. 99 kPa (29.7 inches of Hg) barometric pressure.

b. 29°C (85°F) outside air temperature.

c. 35 API rated fuel.

On a turbocharged and aftercooled engine, a change in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Be sure that the air inlet or exhaust does not have a restriction when making a check of pressure in the inlet manifold.

Inlet manifold plug for pressure test.

Use the 1U5470 Engine Pressure Group to check the pressure in the inlet manifold.

1U5470 Engine Pressure Group

This tool group has a indicator to read pressure in the inlet manifold. Special Instruction SEHS8907 is with the tool group and gives instructions for its use.

Turbocharger

If any unusual sound or vibration in the turbocharger is noticed, a quick check of bearing condition can be made without disassembling the turbocharger. This can be done by removing the piping from the turbocharger and inspecting the compressor impeller, turbine wheel and compressor cover. Rotate the compressor and turbine wheel assembly by hand and observe by feeling excess end play and radial clearance. The rotating assembly should rotate freely with no rubbing or binding. If there is any indication of the impeller rubbing the compressor cover or the turbine wheel rubbing the turbine housing, recondition the turbocharger or replace with a new or rebuilt one.

End clearance is best checked with a dial indicator. Attach a dial indicator with the indicator point on the end of the shaft. Move the shaft from end to end making note of the total indicator reading.

End play for the turbocharger should be 0.08 to 0.25 mm (.003 to .010 in). Maximum permissible end play for the turbocharger is 0.20 mm (.008 in). If end play is more than the maximum end play, rebuild or replace the turbocharger. End play less than the minimum end play could indicate carbon build up on the turbine wheel and the turbocharger should be disassembled for cleaning and inspection.

Checking Turbocharger Rotating Assembly End Play
(Typical Example)

A more reliable check of bearing conditions can be made only when the turbocharger is disassembled and the bearings, shaft journal and housing bore diameters can actually be measured.

Exhaust Temperature

Use the 1U8865 Infrared Thermometer to check exhaust temperature. The Operator's Manual NEHS0510, for the 1U8865 Infrared Thermometer gives complete operating and maintenance instructions for this tool.

Crankcase (Crankshaft Compartment) Pressure

Pistons or rings that have damage can be the cause of too much pressure in the crankcase. This condition may cause the engine to run rough. There will also be more than the normal amount of fumes (blowby) coming from the crankcase breather. The breather can then become restricted in a very short time, causing oil leakage at gaskets and seals that would not normally have leakage. Other sources of blowby can be worn valve guides or turbocharger seal leakage.

8T2700 Indicator Group

The 8T2700 Indicator Group is used to check the amount of blowby. The test procedure is in Special Instruction SEHS8712.

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Removal of the head and inspection of the valves and valve seats is necessary to find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.

Cylinder Head

The cylinder head has valve seat inserts, valve guides and bridge dowels that can be removed when they are worn or have damage. Replacement of these components can be made with the tools that follow.

Valves

Valve removal and installation is easier with use of the 5S1330 Valve Spring Compressor Assembly and 5S1322 Valve Keeper Inserter.

Valve Seat Inserts

Tools needed to remove and install valve seat inserts are in the 6V4805 Valve Insert Puller Group. Special Instruction SMHS7935 gives an explanation for the procedure to remove the valve seat inserts. For easier installation, lower the temperature of the insert before it is installed in the head.

Valve Guides

Tools needed to remove and install valve guides are the 5P2396 Driver Bushing and 9U7349 Driver. The counterbore in the driver bushing installs the guide to the correct height. Use a 1P7451 Valve Guide Honing Group to make a finished bore in the valve guide after installation of the guide in the head. Special Instruction SMHS7526 gives an explanation for this procedure. Grind the valves after the new valve guides are installed.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction GMG02562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Bridge Dowel

Use a 5P0944 Dowel Puller Group with a 5P0942 Extractor to remove the bridge dowels. Install a new bridge dowel with a 5P2406 Dowel Driver. This dowel driver installs the bridge dowel to the correct height.

Bridge Adjustment

When the head is disassembled, keep the bridges with their respective cylinders. Adjustment of the bridge will be necessary after the valves are ground or other reconditioning of the cylinder head is done. The bridge should be checked and/or adjusted each time the valves are adjusted. To check for wear use a dial indicator to measure the amount of wear on the bridge seat. Make sure the contact point on the dial indicator is small enough in diameter to get an accurate measurement.

Dimensions For Reconditioning Bridge Seat

(A) Minimum dimension after reconditioning ... 16.51 mm (.650 in).

(B) Allowable wear before reconditioning ... 0.13 mm (.005 in).

Use the bridge again if the wear is 0.13 mm (.005 in) or less. When the wear seat is worn more than the allowable limit, the worn surface of the seat can be ground flat. The maximum amount of material that can be removed is 0.38 mm (.015 in). If the seat cannot be made flat, replace the bridge. Reconditioning of the wear seat can only be done once.

Use the procedure that follows to make an adjustment to the bridge.

NOTE: Valves must be fully closed.

Bridge Adjustment

1. Put engine oil on the bridge dowel in the cylinder head and in the bore in the bridge.

2. Install the bridge with the adjustment screw toward the exhaust manifold.

3. Loosen the locknut for the adjustment screw and loosen the adjustment screw several turns.

4. Put a force on the bridge with a finger to keep the bridge in contact with the valve stem opposite the adjustment screw.

5. Turn the adjustment screw clockwise until it just makes contact with the valve stem. Then turn the adjustment screw 30 degrees more in a clockwise direction to make the bridge straight on the dowel, and to make compensation for the clearance in the threads of the adjustment screw.

6. Hold the adjustment screw in this position and tighten the locknut to 30 ± 4 N·m (22 ± 3 lb ft).

7. Put engine oil at the point where the rocker arm makes contact with the bridge.

Valve Lash Setting

NOTE: Valve lash is measured between the rocker arm and the bridge for the valves.

NOTE: When the valve lash is checked, adjustment is not necessary if the measurement is in the range given in the chart for Valve Lash Check: Engine Stopped. If the measurement is outside this range, adjustment is necessary. See the chart for Valve Lash Setting: Engine Stopped, and make the setting to the nominal (desired) specifications in this chart.

Valve Lash Check

To make an adjustment to the valve lash, turn the adjustment screw in the rocker arm. Valve lash adjustments can be made by using the procedure that follows:

1. Put No. 1 piston at top center (TC) on the compression stroke. Make reference to Finding Top Center Compression Position For No. 1 Piston.

2. Make an adjustment to the valve lash on the inlet valves for cylinders 1, 2 and 4. Make an adjustment to the valve lash on the exhaust valves for cylinders 1, 3, and 5.

Valve Adjustment

3. After each adjustment, tighten the nut for valve adjustment screw to 30 ± 4 N·m (22 ± 3 lb ft), and check the adjustment again.

4. Remove the timing bolt and turn the flywheel 360 degrees in the direction of engine rotation. This will put No. 6 piston at top center (TC) on the compression stroke. Install the timing bolt in the flywheel.

5. Make an adjustment to the valve lash on the inlet valves for cylinders 3, 5, and 6. Make an adjustment to the valve lash on the exhaust valves for cylinders 2, 4, and 6.

6. Remove the timing bolt from the flywheel when all adjustments to the valve lash have been made.

Cylinder And Valve Location

Lubrication System

One of the problems in the list that follows will generally be an indication of a problem in the lubrication system for the engine.

* Too Much Oil Consumption

* Oil Pressure Is Low

* Oil Pressure Is High

* Too Much Bearing Wear

* Increased Oil Temperature

Too Much Oil Consumption

Oil Leakage On Outside Of Engine

Check for leakage at the seals at each end of the crankshaft. Look for leakage at the oil pan gasket and all lubrication system connections. Check to see if oil comes out of the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty crankcase breather will cause high pressure in the crankcase, and this will cause gasket and seal leakage.

Oil Leakage Into Combustion Area Of Cylinders

Oil leakage into the combustion area of the cylinders can be the cause of blue smoke. There are four possible ways for oil leakage into the combustion area of the cylinders:

1. Oil leakage between worn valve guides and valve stems.

2. Worn or damaged piston rings, or dirty oil return holes

3. Compression ring and/or intermediate ring not installed correctly.

4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.

Too much oil consumption can also be the result if oil with the wrong viscosity is used. Oil with a thin viscosity can be caused by fuel leakage into the crankcase, or by increased engine temperature.

Measuring Engine Oil Pressure

An oil pressure indicator that has a defect can give an indication of low oil pressure.

The 1U5470 Engine Pressure Group can be used to check engine oil pressure.

1U5470 Engine Pressure Group

This tool group has a indicator to read oil pressure in the engine. Special Instruction SEHS8907 is with the tool group and gives instructions for the test procedure.

1. Be sure that the engine is filled to the correct level with SAE 10W30 oil. If any other viscosity of oil is used, the information in the Engine Oil Pressure Graph does not apply.

Oil Manifold (Right Side Of Engine)
(1) Pressure test location.

Oil Pressure Indicator Connection (Left Side Of Engine)
(2) Pressure test location.

2. Connect the 1U5470 Engine Pressure Group to the main oil manifold at location (1) or location (2).

3. Operate the engine to get it up to normal operating temperature.

4. Keep the oil temperature constant with the engine at its rated rpm, and read the pressure indicator.

NOTE: Make sure engine oil temperature does not go above 115°C (239°F).

5. On the Engine Oil Pressure Graph, find the point that the lines for engine rpm and oil pressure intersect (connect).

Engine Oil Pressure Graph

6. If the results do not fall within the "ACCEPTABLE" pressure range given in the graph, find the cause and correct it. Engine failure or a reduction in engine life can be the result if engine operation is continued with oil manifold pressure outside this range.

NOTE: A record of engine oil pressure, kept at regular intervals, can be used as an indication of possible engine problems or damage. If there is a sudden increase or decrease of 70 kPa (10 psi) in oil pressure, even though the pressure is in the "ACCEPTABLE" range on the graph, the engine should be inspected and the problem corrected.

Oil Pressure Is Low

Crankcase Oil Level

Check the level of the oil in the crankcase. Add oil if needed. It is possible for the oil level to be too far below the oil pump supply tube. This will cause the oil pump to not have the ability to supply enough lubrication to the engine components.

Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the oil pump can have a restriction. This will cause cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) and a loss of oil pressure. Air leakage in the supply side of the oil pump will also cause cavitation and loss of oil pressure. If the bypass valve for the oil pump is held in the open (unseated) position, the lubrication system can not get to a maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter Bypass Valves

If the bypass valve for the oil filter is held in the open position (unseated) because the oil filter has a restriction, a reduction in oil pressure can result. To correct this problem, remove and clean the bypass valve and bypass valve bore. Install a new Caterpillar oil filter to be sure that no more debris makes the bypass valve stay open.

Too Much Clearance At Engine Bearings Or Open Lubrication System (Broken Or Disconnected Oil Line Or Passage)

Components that are worn and have too much bearing clearance can cause oil pressure to be low. Low oil pressure can also be caused by an oil line or oil passage that is open, broken or disconnected.

Piston Cooling Tubes (Jets)

When the engine is operated, cooling jets direct oil toward the bottom of the piston to lower piston and ring temperatures. If there is a failure of one of the jets, or it is bent in the wrong direction, seizure of the piston will be caused in a very short time.

To eliminate the possibility of damaging piston cooling jets during removal of the connecting rod cap, the piston cooling jet assembly should always be removed. The wider connecting rod cap design, cannot be removed without damaging the "double tube" cooling jet design.

Use the 5P8709 Piston Tool Group to check and adjust the alignment of piston cooling jets.

NOTE: This tool group does not currently accommodate the double tube jet design.

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the oil pump can not move from the closed position.

Too Much Bearing Wear

When some components of the engine show bearing wear in a short time, the cause can be a restriction in an oil passage.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it can not get enough lubrication, look at the passage for oil supply to the component. A restriction in a supply passage will not let enough lubrication get to a component, and this will cause early wear.

Increased Oil Temperature

Look for a restriction in the oil passages of the oil cooler. If the oil cooler has a restriction, the oil temperature will be higher than normal when the engine is operated. The oil pressure of the engine will not get low just because the oil cooler has a restriction.

Also check the oil cooler bypass valve to see if it is held in the open position (unseated). This condition will let oil through the valve instead of the oil cooler, and oil temperature will increase.

Cooling System

This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

The cause for increased engine temperature is generally because regular inspections of the cooling system were not made. Make a visual inspection of the cooling system before a test is made with test equipment.

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

NOTE: Water pump seals. A small amount of coolant leakage across the surface of the "face-type" seals is normal, and required, to provide lubrication for this type of seal. A hole is provided in the water pump housing to allow this coolant/seal lubricant to drain from the pump housing. Intermittent leakage of small amounts of coolant from this hole is not an indication of water pump seal failure. Replace the water pump seals only if a large amount of leakage, or a constant flow of coolant is observed draining from the water pump housing.

3. Look for bent radiator fins. Be sure that air flow through the radiator does not have a restriction.

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

6. Look for air or combustion gas in the cooling system.

7. Inspect the filler cap and the surface that seals the cap. This surface must be clean.

Testing The Cooling System

Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, temperature and pressure must both be checked. Cooling system pressure will have an effect on cooling system temperatures. For an example, look at the chart to see the effect of pressure and height above sea level on the boiling (steam) point of water.

Test Tools for Cooling System

4c6500 Digital Thermometer Group

The 4C6500 Digital Thermometer Group is used in the diagnosis of overheating (engine hotter than normal) or overcooling (engine cooler than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Operating Manual NEHS0554.

8T2700 Blowby/Air Flow Indicator Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The test procedure is in Special Instruction SEHS8712.

6V3121 Multitach Group

The 6V3121 Multitach Group is used to check the fan speed. The testing procedure is in Special Instruction SEHS7807.

9S8140 Cooling System Pressurizing Pump Group

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and to pressure check the cooling system for leaks.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

Checking Pressure Cap

One cause for a pressure loss in the cooling system can be a defective seal on the radiator pressure cap.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

After the engine is cool, loosen the pressure cap and let the pressure out of the cooling system. Then remove the pressure cap.

Typical Schematic Of Pressure Cap
(A) Sealing surface of cap and radiator.

Inspect the pressure cap carefully. Look for damage to the seal or to the surface that seals. Any foreign material or deposits on the cap, seal or surface that seals, must be removed.

The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and to pressure check the cooling system for leaks.

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

To check the pressure cap for the pressure that makes the pressure cap open, use the procedure that follows:

1. Remove the pressure cap from the radiator.

2. Put the pressure cap on the 9S8140 Cooling System Pressurizing Pump Group.

3. Look at the indicator for the exact pressure that makes the pressure cap open.

4. Make a comparison of the reading on the indicator with the correct pressure at which the pressure cap must open.

NOTE: The correct pressure that makes the pressure cap open is on the pressure cap and is also in the Specifications module.

5. If the pressure cap is defective, install a new pressure cap.

Testing Radiator And Cooling System For Leaks

To test the radiator and cooling system for leaks, use the procedure that follows:

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DO NOT loosen the filler or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

1. Remove the pressure cap from the radiator.

2. Make sure the coolant is over the top of the radiator core.

3. Put the 9S8140 Cooling System Pressurizing Pump Group on the radiator.

4. Operate the pump group and get a pressure reading on the indicator that is 20 kPa (3 psi) more than the pressure marked on the pressure cap.

5. Check the radiator for outside leakage.

6. Check all connections and hoses for the cooling system for outside leakage.

7. If you do not see any outside leakage and the pressure reading on the indicator is still the same after five minutes, the radiator and cooling system does not have leakage. If the reading on the indicator goes down and you do not see any outside leakage, there is leakage on the inside of the cooling system. Make repairs as necessary.

Indicator For Water Temperature

4C6500 Digital Thermometer Group

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the indicator for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place can not be found where there is coolant leakage check the accuracy of the indicator for water temperature. A temperature indicator of known accuracy can be used to make this check. Also, the 4C6500 Digital Thermometer Group may be used.

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Work carefully around an engine that is running. Engine parts that are hot, or parts that are moving, can cause personal injury.

Water Temperature Indicator

Start the engine and run it until the temperature is at the desired range according to the test indicator or thermometer. If necessary, put a cover over part of the radiator or cause a restriction of the coolant flow. The reading on the indicator for water temperature must be the same as the test indicator or thermometer within the tolerance range in the chart.

Water Temperature Regulators

1. Remove the regulator from the engine.

2. Heat water in a pan until the temperature is 98°C (208°F). Move the water around in the pan to make it all the same temperature.

3. Hang the regulator in the pan of water. The regulator must be below the surface of the water and it must be away from the sides and bottom of the pan.

4. Keep the water at the correct temperature for ten minutes.

5. After ten minutes, remove the regulator and immediately measure the distance the regulator has opened. The distance must be a minimum of 9.53 mm (.375 in).

6. If the distance is less than 9.53 mm (.375 in), make a replacement of the regulator.

Belt Tension Chart

Basic Block

Piston Rings

This engine has piston grooves and rings of the KEYSTONE (taper) design. The 1U6431 Gauge Group is available to check the top two ring grooves in the piston. For correct use of the gauge group see the instruction card that is with the gauge group.

Instructions For 1U6431 Gauge Group

Connecting Rods And Pistons

Use the 7M3978 Piston Ring Expander to remove or install piston rings.

Use the 5P3526 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod nuts in the step sequence that follows:

1. Put 4C5593 Thread Lubricant on bolt threads and contact surfaces of nut and cap.

2. Tighten all nuts to 80 ± 8 N·m (60 ± 6 lb ft).

3. Put a mark on each nut and end of bolt.

4. Tighten each nut 120 degrees from the mark.

The connecting rod bearings fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check bore size. This can be an indication of wear because of a loose fit.

Connecting Rod And Main Bearings

Connecting rod bearings are available with 0.63 mm (.025 in) and 1.27 mm (.050 in) smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size).

Main bearings are available with a larger outside diameter than the original size bearings. These bearings are for cylinder blocks that have had the bore for the main bearings "bored" (made larger than the original size). The size available is 0.63 mm (.025 in) larger outside diameter than the original size bearings.

Cylinder Block

1P3537 Dial Bore Gauge Group

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts that hold the caps to the torque shown in the Specifications module. Alignment error in the bores must not be more than 0.08 mm (.003 in). Special Instruction SMHS7606 gives instructions for the use of 1P4000 Line Boring Tool Group for alignment of the main bearing bores. The 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction GMG00981 is with the group.

Cylinder Liner Projection

NOTE: This procedure alleviates the need for the "H" bar to hold down liners during projection measurements.

Liner Projection Components
(1) Bolt. (2) Washer. (3) Washer.

Install clean liners or cylinder packs (without the filler band or the rubber seals), spacer plate gasket and clean spacer plate.

Install bolts and washers, as indicated previously, in the holes. Install all bolts or the six bolts around the liner. Tighten the bolts to a torque of 95 N·m (70 lb ft).

Use the 8T0455 Liner Projection Tool Group to measure liner projection at positions indicated with an A, B, C and D. Record measurements for each cylinder. Add the four readings for each cylinder and divide by four to find the average.

If the liner projections are out of specification, try rotating the liner or install the liner in another bore to see if the measurements improve.

If the liner projections are all below the specifications or low in the range, 0.025 mm (0.001 in) or 0.051 mm (0.002 in), try using a thinner spacer plate (6I3189 or 6I4303). These plates are 0.076 mm (0.003 in) thinner than the regular plate and they will increase the liner projection, thus increasing the fire ring crush. Use these spacer plates to compensate for low liner projections that are less than 0.076 mm (0.003 in) or if the inspection of the top deck reveals no measurable damage directly under the liner flanges, but the average liner projection is less than 0.076 mm (0.003 in).

Do not exceed the maximum liner projection of 0.152 mm (0.006 in). Excessive liner projection will contribute to liner flange cracking.

With the proper liner projection, mark the liners in the proper position and set them aside.

When the engine is ready for final assembly, the O-ring seals, cylinder block and upper filler band must be lubricated before installation.

NOTE: Apply clean engine oil immediately before assembly. If applied too early, the seals may swell and be pinched under the liners during installation.

Flywheel And Flywheel Housing

Heat the ring gear to install it. Do not heat to more than 315°C (600°F). Install the ring gear so the chamfer on the gear teeth are next to the starter pinion when the flywheel is installed.

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

If any method other than given here is used, always remember bearing clearance must be removed to get correct measurements.

8T5096 Dial Indicator Group Installed

Checking Face Runout Of The Flywheel Housing
(A) Bottom. (B) Right side. (C) Top. (D) Left side.

1. Fasten a dial indicator to the crankshaft flange so the anvil of the indicator will touch the face of the flywheel housing.

2. Put a force on the crankshaft toward the rear before the indicator is read at each point.

3. With dial indicator set at 0.0 mm (.000 in) at location (A), turn the crankshaft and read the indicator at locations (B), (C) and (D).

4. The difference between lower and higher measurements taken at all four points must not be more than 0.38 mm (.015 in), which is the maximum permissible face run out (axial eccentricity) of the flywheel housing.

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

8T5096 Dial Indicator Group Installed

1. Fasten the dial indicator as shown so the anvil of the indicator will touch the bore of the flywheel housing.

2. With the dial indicator in position at (C), adjust the dial indicator to "0" (zero). Push the crankshaft up against the top of the bearing. Write the measurement for bearing clearance on line 1 in column (C) in the chart for dial indicator measurements.

NOTE: Write the dial indicator measurements with their positive (+) and negative (-) notation (signs). This notation is necessary for making the calculations in the chart correctly.

3. Divide the measurement from Step 2 by 2. Write this number on line I in columns (B) & (D).

4. Turn the crankshaft to put the dial indicator at (A). Adjust the dial indicator to "0" (zero).

5. Turn the crankshaft counterclockwise to put the dial indicator at (B). Write the measurements in the chart.

Checking Bore Runout Of The Flywheel Housing

6. Turn the crankshaft counterclockwise to put the dial indicator at (C). Write the measurement in the chart.

7. Turn the crankshaft counterclockwise to put the dial indicator at (D). Write the measurement in the chart.

8. Add lines I and II by columns

9. Subtract the smaller number from the larger number in line III in columns (B) & (D). The result is the horizontal eccentricity (out of round). Line III, column (C) is the vertical eccentricity.

10. On the graph for total eccentricity find the point of intersection of the lines for vertical eccentricity and horizontal eccentricity.

11. If the point of intersection is in the range marked "Acceptable" the bore is in alignment. If the point of intersection is in the ranged marked "Not Acceptable" the flywheel housing must be changed.

Graph For Total Eccentricity
(1) Total vertical eccentricity [mm (in)]. (2) Total horizontal eccentricity [mm (in)]. (3) Acceptable. (4) Not acceptable.

Face Runout (Axial Eccentricity) Of The Flywheel

1. Install the dial indicator as shown. Always put a force on the crankshaft in the same direction before the indicator is read so the crankshaft end clearance (movement) is always removed.

Checking Face Runout Of The Flywheel

2. Set the dial indicator to read 0.0 mm (.000 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not be more than 0.15 mm (.006 in), which is the maximum permissible face runout (axial eccentricity) of the flywheel.

Bore Runout (Radial Eccentricity) Of The Flywheel

Checking Bore Runout Of The Flywheel
(1) 7H1945 Holding Rod. (2) 7H1645 Holding Rod. (3) 7H1942 Indicator. (4) 7H1940 Universal Attachment.

1. Install the dial indicator (3) and make an adjustment of the universal attachment (4) so it makes contact as shown.

2. Set the dial indicator to read 0.0 mm (.000 in).

3. Turn the flywheel and read the indicator every 90 degrees.

4. The difference between the lower and higher measurements taken at all four points must not be more than ... 0.15 mm (.006 in)

Vibration Damper

Damage to or failure of the damper will increase vibrations and result in damage to the crankshaft and may cause more gear train noise at certain engine speeds.

Vibration Damper
(1) Alignment marks.

The vibration damper has marks (1) on the hub and the ring. These marks give an indication of the condition of the vibration damper. If the marks are not in alignment, the rubber part (between the ring and the hub) of the vibration damper has had a separation from the ring and/or hub. Install a new vibration damper.

A used vibration damper can have a visual wobble (movement to the front and then to the rear when in rotation) on the outer ring and still not need replacement, because some wobble of the outer ring is normal. To see if the amount of wobble is acceptable, or replacement is necessary, check the damper with the procedure that follows:

1. Install a dial indicator, contact point and other parts as necessary to hold the dial indicator stationary. The contact point must be perpendicular (at 90° angle) to the face of the outer ring of the damper, and must make contact approximately at the center of the outer ring.

2. Push on the front end of the crankshaft so the end play (free movement on the centerline) is removed. Keep the crankshaft pushed back until the measurements are done.

3. Adjust the dial indicator to zero.

4. Turn the crankshaft 360 degrees and watch the dial indicator. A total indicator reading of 0.00 to 2.03 mm (.000 to .080 in) is acceptable.

Mechanical Oil Pressure And Water Temperature Shutoff

Mechanical Oil Pressure And Water Temperature Shutoff (Typical Illustration)
(1) Outlet line. (2) Inlet line. (3) Drain line. (4) Shut down cylinder knob. (5) Water temperature control valve. (6) Shut down cylinder inlet port. (7) Oil pressure shut down cylinder. (8) Oil pressure control valve.

1. Make a restriction to the flow of air through the radiator or to the flow of coolant through the engine.

2. Install a probe from the 4C6500 Thermometer Group as close as possible to the water temperature control valve (5).

3. Start the engine. The engine must stop in one minute or less from the time the temperature of the coolant gets to the opening temperature of the control valve. If the engine does not stop, do the steps that follow.

4. Stop the engine. Disconnect oil lines (1, 2 and 3) from the control valve.

5. Remove the water temperature control valve (5) from the engine and install the 3J5389 Plug in its place.

6. Connect a 5P8869 Connector and a 4K7965 Hose Assembly to lines (1, 2 and 3).

7. Connect a 60210 Tee on the hose assembly connected to lines (1 and 2).

8. Connect the last 4K7965 Hose Assembly to the last opening of the tee.

9. Connect the other 60210 Tee to the open end of this hose assembly.

10. Connect a 5P7486 Valve to the other end of this 60210 Tee.

11. Connect the open end of the hose assembly connected to line (3) to the open end of the 5P7486 Valve.

12. Connect the 8T0848 Indicator on the open end of the 60210 Tee.

13. Start the engine. Run the engine at full load rpm.

14. Slowly open the 5P7486 Valve. Look at the pressure indicator. Oil pressure shut down circuitry must stop the engine when the oil pressure is between 69 and 96.6 kPa (10 and 14 psi). If the engine does not stop the oil pressure shutoff valve (8) or the oil pressure shut down cylinder (7) have a failure or there could be a restriction in the lines (1, 2 or 3).

15. To check the oil pressure shutoff valve (8) and the oil pressure shutdown cylinder, remove line (6). With extra tubing direct line (6) into the engine oil filler port. Repeat Steps 13 and 14. Instead of the engine shutting down a stream of oil should exit line (6) into the engine oil filler port. If this does not happen line (6) could have a restriction or the oil pressure shutoff valve (8) has a failure.

NOTE: A small trickle of oil will always exit line (6) but will change to a stream when the oil pressure shutoff valve (8) is activated. This is because the oil pressure shutoff valve (8) consists of a pilot valve and a control valve.

16. Make repairs as necessary and repeat Steps 13 and 14.

17. When oil exits line (6) properly at the correct pressure install line (6). Repeat Steps 13 and 14. If the engine still does not shut down replace the oil pressure shut down cylinder.

18. When the oil pressure shutoff stops the engine at correct pressure remove the tools and install the control valve (5).

19. Do Steps 1, 2 and 3 again. If the control valve (5) does not cause the engine to stop make a replacement of the control valve.

Electrical System

Test Tools For Electrical System

Most of the tests of the electrical system can be done on the engine. The wiring insulation must be in good condition, the wire and cable connections must be clean and tight, and the battery must be fully charged. If the on-engine test shows a defect in a component, remove the component for more testing.

The service manual Testing And Adjusting Electrical Components REG00636 has complete specifications and procedures for the components of the starting circuit and the charging circuit.

4C4911 Battery Load Tester

The 4C4911 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to load test all 6, 8 and 12V batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load adjustment knob on the top permits the current being drawn from the battery to be adjusted to a maximum of 1000 amperes. The tester is cooled by an internal fan that is automatically activated when a load is applied.

The tester has a built in LCD digital voltmeter and amperage meter. The digital voltmeter accurately measures the battery voltage at the battery through tracer wires buried inside the load cables. The digital amperage meter accurately displays the current being drawn from the battery under test.

NOTE: Make reference to Operating Manual SEHS9249 for more complete information for use of the 4C4911 Battery Load Tester.

6V7070 Heavy-Duty Digital Multimeter

The 6V7070 Heavy-Duty Digital Multimeter is a completely portable, hand held instrument with a digital display. This multimeter is built with extra protection against damage in field applications, and is equipped with seven functions and 29 ranges. The 6V7070 Multimeter has an instant ohms indicator that permits continuity checks for fast circuit inspection. It also can be used for troubleshooting small value capacitors.

The 6V7800 Regular-Duty Digital Multimeter (a low cost option to the Heavy-Duty Multimeter) is also available; however, the 6V7800 Multimeter does not have the 10A range or the instant ohms feature of the 6V7070 Multimeter.

NOTE: Make reference to Special Instruction SEHS7734 for more complete information for use of the 6V7070 and 6V7800 Multimeters.

Battery

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Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is operated. A spark can cause an explosion from the flammable vapor mixture of hydrogen and oxygen that is released from the electrolyte through the battery outlets. Injury to personnel can be the result.

Before any testing is done on the electrical system, the batteries should be checked for good connections and must be at least 75% (1.225 Sp Gr) fully charged.

The battery circuit is an electrical load on the charging unit. The load is variable because of the condition of the charge in the battery. Damage to the charging unit will result if the connections (either positive or negative) between the battery and charging unit are broken while the charging unit is in operation. This is because the battery load is lost and there is an increase in charging voltage. High voltage will damage, not only the charging unit, but also the regulator and other electrical components.

Use the 4C4911 Battery Load Tester to load test a battery that does not hold a charge when in use. Refer to Operating Manual SEHS9249 for more detailed instructions on use of the 4C4911 Battery Load Tester. See Special Instruction SEHS7633 for the correct procedure and specifications to use when testing batteries.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system operates correctly. An adjustment is necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water per cell per week or per every 100 service hours).

When it is possible, make a test of the charging unit and voltage regulator on the engine, and use wiring and components that are a permanent part of the system. Off-engine (bench) testing will give a test of the charging unit and voltage regulator operation. This testing will give an indication of needed repair. After repairs are made, again make a test to give proof that the units are repaired to their original condition of operation.

To check for correct output of the alternator, see the Specifications module.

For complete service information, refer to Service Manual Module SENR3862, Delco Remy 27-SI Series Alternators. This module is part of REG00636 Service Manual.

Before the start of on-engine testing, the charging system and battery must be checked as shown in the Steps that follow:

1. Battery must be at least 75% (1.225 Sp.Gr.) fully charged and held tightly in place. The Battery holder must not put too much stress on the battery.

2. Cables between the battery, starting motor and engine ground must be the correct size. Wires and cables must be free of corrosion and have cable support clamps to prevent stress on battery connections (terminals).

3. Leads, junctions, switches, and panel instruments that have direct relation to the charging circuit must give correct circuit control.

4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and have the ability to operate the charging unit.

Alternator Regulator Adjustment

When an alternator is charging the battery too much or not enough, the charging rate of the alternator should be checked. Make reference to the Specifications module to find all testing specifications for the alternators and regulators.

No adjustment can be made to change the rate of charge on the alternator regulators. If rate of change is not correct, a replacement of the regulator is necessary.

Alternator Pulley Nut Tightening

Refer to the Specifications for the torque for the alternator pulley nut.

Tools To Tighten Alternator Pulley Nut
(1) 8T9293 Torque Wrench. (2) 8S1588 Adapter (1/2 inch female to 3/8 inch male). (3) 2P8267 Socket Assembly. (4) 8H8517 Combination Wrench (11/8 inch). (5) 8T5314 Socket.

Starting System

Use the multimeter in the DCV range to find starting system components which do not function.

Move the start control switch to activate the starter solenoid. Starter solenoid operation can be heard as the pinion of the starting motor is engaged with the ring gear on the engine flywheel.

If the solenoid for the starting motor will not operate, it is possible that the current from the battery did not get to the solenoid. Fasten one lead of the multimeter to the connection (terminal) for the battery cable on the solenoid. Put the other lead to a good ground. A zero reading is an indication that there is a broken circuit from the battery. More testing is necessary when there is a voltage reading on the multimeter.

The solenoid operation also closes the electric circuit to the motor. Connect one lead of the multimeter to the solenoid connection (terminal) that is fastened to the motor. Put the other lead to a good ground. Activate the starter solenoid and look at the multimeter. A reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. A zero reading on the multimeter shows that the solenoid contacts do not close. This is an indication of the need for repair to the solenoid or an adjustment to be made to the starter pinion clearance.

Make a test with one multimeter lead fastened to the connection (terminal) for the small wire at the solenoid and the other lead to the ground. Look at the multimeter and activate the starter solenoid. A voltage reading shows that the problem is in the solenoid. A zero reading is an indication that the problem is in the start switch or the wires for the start switch.

Fasten one multimeter lead to the start switch at the connection (terminal) for the wire from the battery. Fasten the other lead to a good ground. A zero reading indicates a broken circuit from the battery. Make a check of the circuit breaker and wiring. If there is a voltage reading, the problem is in the start switch or in the wires for the start switch.

A starting motor that operates too slow can have an overload because of too much friction in the engine being started. Slow operation of the starting motor can also be caused by a short circuit, loose connections and/or dirt in the motor.

Pinion Clearance Adjustment

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starting motor removed.

Connection For Checking Pinion Clearance
(1) Connector (from MOTOR terminal on solenoid to the motor). (2) Terminal (3) Ground terminal.

1. With the solenoid installed on the starting motor, remove connector (1).

2. Connect a battery, of the same voltage as the solenoid, to the terminal (2), marked SW.

3. Connect the other side of the battery to ground terminal (3).

4. Connect for a moment a wire from the solenoid connection (terminal) marked MOTOR to the ground connection (terminal). The pinion will shift to crank position and will stay there until the battery is disconnected.

Pinion Clearance Adjustment
(4) Nut. (5) Pinion. (6) Pinion clearance.

5. Push the pinion toward the commutator end to remove free movement.

6. Pinion clearance (6) must be 8.3 to 9.9 mm (.33 to .39 in).

7. To adjust pinion clearance, remove plug and turn nut (4).

8. After the adjustment is completed, install the plug over adjustment nut (4) and install connector (1) between the MOTOR terminal on the solenoid and the starting motor.

Rack Shutoff Solenoid

Adjust, if necessary, the distance (2) between the shaft and the plate to 24.4 mm (.96 in) at the start of the test.

Rack Solenoid
(1) Travel 15.7 mm (.62 in). (2) Distance between shaft and plate 24.4 mm (.96 in). (3) Start position of plunger plate from mounting flange is 11.2 mm (.44 in) to measure travel of plunger.

Two checks must be made on the engine to give proof that the solenoid adjustment is correct.

1. The adjustment must give the plunger enough travel to move the rack to the fuel shutoff position. Use the 9S0240 Rack Position Tool Group to make sure the rack goes to the fuel shutoff position.

2. The adjustment must give the plunger enough travel to cause only the "hold-in" windings of the solenoid to be activated when the rack is held in the fuel shutoff position. Use a thirty ampere ammeter to make sure the plunger is in the "hold-in" position. Current needed must be less than two amperes.

Rack Solenoid
(1) Solenoid plunger. (2) Stop bolt. (3) Locknut. (4) Lock wire and seal.

1. Remove any manual shutoff shaft linkage from the governor.

2. Remove lock wire and seal (4). Loosen locknut (3) and turn stop bolt (2) several turns out [away from solenoid plunger (1)]

3. Rotate the manual shutoff shaft clockwise to the shutoff position. Fasten the shaft in the shutoff position.

4. Hold locknut (3) and turn stop bolt (2) in until the bolt contacts shutoff solenoid plunger (1).

5. Turn stop bolt (2) in an additional 3/4 ± 1/4turn and tighten locknut (3).

6. Release the manual shutoff shaft.

7. Start the engine.

8. The engine should run at low idle without a problem.

9. To test the solenoid stop bolt adjustment, run the engine at high idle and no load. Shut off the engine and the engine should stop.

10. If the engine continues to run at reduced speed or shuts down too slowly, turn the stop bolt (2) out an additional 1/4 turn and repeat Step 9.

11. If possible, apply a load to the engine and make sure the engine will maintain the normal full load speed. Remove the load and return the engine to low idle.

12. Shut off the engine.

Air Starting System

Pressure Regulating Valve

Pressure Regulating Valve (Typical Illustration)
(1) Adjustment screw. (2) Regulator inlet. (3) Regulator outlet.

To check and adjust the pressure regulating valve, use the procedure that follows:

1. Drain the line to the pressure regulating valve or drain the air storage tank.

2. Disconnect the regulator from the starter control valve.

3. Connect an 8M2885 Pressure Indicator to regulator outlet (3).

4. Put air pressure in the line or tank.

5. Check the pressure.

6. Adjust the pressure regulating valve as shown in Chart For Air Pressure Setting.

7. Remove the air pressure from the line or tank.

8. Remove the 8M2885 Pressure Indicator and connect the air pressure regulator to the line to the air starting motor.

Each engine application will have to be inspected to get the most acceptable starting results. Some of the factors that affect regulating valve pressure setting are: attachment loads pulled by engine during starting, ambient temperature conditions, oil viscosity, capacity of air reservoir, and condition of engine (new or worn).

The advantage of setting the valve at the higher pressures is increased torque for starting motor and fastener rotation of engine. The advantage of setting the valve at the lower pressures is longer time of engine rotation for a given reservoir capacity of supply air.

Lubrication

Always use an air line lubricator with these air starting motors.

For temperatures above 0°C (32°F), use a non detergent 10W engine oil.

For temperatures below 0°C (32°F), use air tool oil.

Air Starting Motor

Components Of The Air Starting Motor
(1) Motor housing cover. (2) Plug. (3) Plug. (3A) Plug. (6) Bolt (cap screw). (7) Lockwasher. (8) Gasket. (9) Rotor rear bearing. (10) Bearing retainer. (11) Rear end plate. (12) Cylinder. (13) Dowel. (14) Rotor vane. (15) Rotor. (16) Front end plate. (17) Rotor front bearing. (18) Motor housing. (19) Gear case gasket. (20) Rotor pinion. (21) Rotor pinion retainer. (22) Gear case. (23) Bearing rejecting washer. (24) Rear bearing (for the drive shaft). (25) Drive gear. (25A) Thrust washer. (26) Key (for the drive gear). (27) Front bearing (for the drive shaft). (28) Gear case cover. (29) Grease seal (for the drive shaft). (30) Cover seal. (31) Piston seal. (32) Bolt. (33) Lockwasher. (34) Drive shaft. (35) Drive shaft collar. (36) Piston. (36A) Piston ring. (37) Shift ring. (38) Shift ring retainer. (39) Shift ring spacer. (40) Piston return spring. (41) Return spring seat. (42) Starter drive (pinion). (43) Lockwasher. (44) Bushing (for the bolts). (45) Drive housing. (46) Drive housing bushing. (47) Oiler felt (for the bushing). (48) Oiler plug.

Rear View Of The Cylinder And Rotor For Clockwise Rotation
(12) Cylinder. (12A) Air inlet passages. (12B) Dowel hole. (15) Rotor.

Air Starting Motor
(6) Bolt. (12) Cylinder. (15) Rotor. (16) Front end plate. (22) Gear case. (25) Drive gear. (28) Gear case cover. (29) Grease seal. (32) Bolt. (34) Drive shaft. (35) Drive shaft collar. (42) Starter drive (pinion). (45) Drive housing. (49) Air inlet. (50) Deflector (air outlet). (51) Mounting flange (on the drive housing).

The cylinder (12) must be assembled over the rotor (15) and on the front end plate (16) so the dowel hole (12B) and the inlet passages (12A) for the air are as shown in the rear view illustration of the cylinder and rotor. If the installation is not correct, the starter drive (42) will turn in the wrong direction.

Tighten the bolts (6) of the rear cover in small increases of torque for all bolts until all bolts are tight 30 ± 5 N·m (22 ± 4 lb ft).

Put a thin layer of lubricant on the lip of the seal (29) and on the outside of the collar (35), for installation of drive shaft (34). After installation of the shaft through the gear case cover (28) check the lip of the grease seal (29). It must be turned correctly toward the drive gear (25). If the shaft turned the seal lip in the wrong direction, remove the shaft and install again. Use a tool with a thin point to turn the seal lip in the correct direction.

Tighten the bolts (32) of the drive housing in small increases of torque for all bolts until all bolts are tight 11.3 N·m (100 lb in).

Check the motor for correct operation. Connect an air hose to the motor inlet (49) and make the motor turn slowly. Look at the starter drive (42) from the front of the drive housing (45). The pinion must turn clockwise.

Connect an air hose to the small hole with threads in the drive housing (45), nearer the gear case (22). When a little air pressure goes to the drive housing, the starter drive (42) must move forward to the engaged position. Also, the air must get out through the other hole with threads nearer the mounting flange (51).

Instruments And Indicators

Magnetic Pickup

Typical Illustration

(1) Clearance between magnetic pickup and flywheel ring gear ... 0.55 to 0.83 mm (0.022 to .033 in)

NOTE: Turn the pickup in until it comes in contact with the teeth on the flywheel ring gear. Turn the pickup out 1/2 turn. This will give 0.55 to 0.83 mm (.022 to .033 in) clearance at (1).

(2) Tighten the locknut to a torque of ... 45 ± 7 N·m (33 ± 5 lb ft)

Oil Pressure Sending Units

Sending Unit For Oil Pressure
(1) Terminal. (2) Fitting.

1. Connect the sending unit to a pressure source that can be measured with accuracy.

2. Connect an ohmmeter between fitting (2) and terminal (1).

3. Take resistance readings at the pressure shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Water Temperature Sending Units

Sending Unit For Water Temperature
(1) Terminal. (2) Nut. (3) Bulb.

1. Connect an ohmmeter between terminal (1) and nut (2). Put bulb (3) in a pan of water. Do not let the bulb have contact with the pan.

2. Put a thermometer in the water to measure the temperature.

3. Take resistance readings at the temperatures shown in the chart.

4. If a unit does not have the correct resistance readings, make a replacement of the unit.

Electric Indicators

1. Put the indicator in position with the letters horizontal and the face 30 degrees back from vertical.

Wiring Diagram For Test
(1) Terminal (for test voltage). (2) Test resistance.

2. Connect the indicator in series with the power source and the middle test resistance shown in the chart.

3. Let the indicator heat at the middle resistance for five minutes, then check the pointer position for all of the resistance given.

Mechanical Indicators For Temperature

Direct Reading Indicator

To check these indicators, put the bulb of the indicator in a pan of oil. Do not let the bulb touch the pan. Put a thermometer in the oil to measure the temperature. Make a comparison of temperatures on the thermometer with the temperatures on the direct reading indicator.

Mechanical Indicators For Oil Pressure

Direct Reading Indicator

To check these indicators connect the indicator to a pressure source that can be measured with accuracy. Make a comparison of pressure on the indicator of test equipment with the pressures on the direct reading indicator.