Testing & Adjusting

Usage:

Introduction

NOTE: For Specifications with illustrations, make reference to Specifications for 3306B Generator Set Engine, SENR1092. If the Specifications in SENR1092 are not the same as the Systems Operation and the 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 Index 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 recommendation 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 Will Not Turn When Start Switch Is On.

2. Engine Will Not Start.

3. Misfiring Or Running Rough.

4. Stall At Low RPM.

5. Sudden Changes In Engine RPM.

6. Not Enough Power.

7. Too Much Vibration.

8. Loud Combustion Noise (Knock).

9. Loud Noise (Clicking) From Valve Compartment.

10. Oil In Cooling System.

11. Mechanical Noise (Knock) In Engine.

12. Fuel Consumption Too High.

13. Loud Noise From Valves Or Valve Operating Components.

14. Little Movement Of Rocker Arm And 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.

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

Probable Cause:

1. Battery Has Low Output

Make Reference to Problem 12 in SENR1078.

2. Wires Or Switches Have Defect

Make Reference to Problem 12 in SENR1078.

3. Starter Motor Solenoid Has A Defect

Make Reference to Problem 11 in SENR1078.

4. Starter Motor Has A Defect

Make Reference to Problem 11 in SENR1078.

5. Inside Problem Prevents Engine Crankshaft From Turning

If the crankshaft cannot be turned after the drive equipment is disconnected, remove the fuel nozzles and check for fluid in the cylinders while 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, wrong pistons installed in the engine, and valves making contact with pistons.

Problem 2: Engine Will Not Start

Probable Cause:

1. Slow Cranking Speed

Make reference to Problem 12 in SENR1078.

2. No Fuel In The Housing For The Fuel Injection Pumps

Fill the housing for the fuel injection pumps with fuel using the priming pump. Remove the air with the bleed valve.

3. Dirty Fuel Filter

Install new fuel filter.

4. Dirty Or Broken Fuel Lines

Clean or install new fuel lines as necessary.

5. No Fuel To Cylinders

Put fuel in fuel tank. "Prime" (remove the air from the fuel system).

6. Poor Quality Or Water In Fuel

Remove fuel from the fuel tank. Install a new fuel filter element. Put a good grade of clean fuel in the fuel tank. Follow the recommendations given in SEBD0717 Diesel Fuels And Your Engine. Also, Special Instruction, SEHS6947 has fuel correction factors and tables.

7. 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.

8. Wrong Fuel Injection Timing

Make adjustment to timing.

9. Overfueling Spring Not Installed

Install overfueling spring.

Problem 3: Misfiring Or Running Rough

Probable Cause:

1. Air In The Fuel System

Find air leak in the fuel system and correct. Remove air from fuel system. See Fuel System in Testing & Adjusting.

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 at the fuel injection pump housing. If fuel pressure at high idle is lower than 105 kPa (15 psi), install a new filter element. If fuel pressure is still low, check the pumping spring and the check valves in the fuel transfer pump.

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

Install a new fuel line.

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

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the fuel injection nozzle for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the fuel injection pump and fuel injection nozzle for that cylinder. Install new parts where needed.

5. Fuel System Not Timed Correctly To Engine

Make adjustment to timing if necessary.

6. Wrong Valve Lash

Make adjustment. See the Subject Valve Lash in Testing & Adjusting.

7. Bent Or Broken Push Rod

Replacement of push rod is necessary.

8. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed.

Problem 4: Stall At Low RPM

Probable Cause:

1. Idle RPM Too Low

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

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

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the injection pump for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut does not change the way the engine runs. Test the fuel injection pump and fuel injection nozzle for that cylinder. Install new parts where needed.

Problem 5: Sudden Changes In Engine 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 the 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. Air In The Fuel System

Find air leak in the fuel system and correct. Remove air from fuel system. See Fuel System in Testing & Adjusting.

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 at the fuel injection pump housing. If fuel pressure at high idle is lower than 105 kPa (15 psi), install a new fuel filter element. If fuel pressure is still low, check the pumping spring and the check valves in the fuel transfer pump.

3. Poor Quality Or Water In Fuel

4. Constant Bleed Valve Stays Open Or Closed

Install new parts if needed.

5. Leaks In Air Inlet System

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

6. Governor Linkage

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

7. Wrong Valve Lash

Make adjustment. See the Subject Valve Lash in Testing & Adjusting

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

9. Wrong Fuel Injection Timing

Make adjustment to timing.

10. Fuel Setting Too Low

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

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 In Nut Holding Pulley Or Damper

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect

Install a new pulley or damper.

3. Fan Blade Not In Balance

Loosen or remove fan belts and operate engine for a short time at the rpm that the vibration was present. If vibration is not still present, make a replacement of the fan assembly.

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

Tighten all mounting bolts. Install new components if necessary.

5. Misfiring Or Running Rough

Make reference to Problem 3.

Problem 8: Loud Combustion Noise (Knock)

Probable Cause:

1. Poor Quality Or Water In Fuel

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

Run engine at rpm that gives maximum combustion noise. Then loosen a fuel line nut on the fuel injection nozzle for each cylinder, one at a time. Find the cylinder where loosening the fuel line nut stops the combustion noise. Test the fuel injection pump and fuel injection nozzle for that cylinder. Install new parts where needed.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 9: Loud Noise (Clicking) From Valve Compartment

Probable Cause:

1. Damage To Valve Spring(s) Or Locks

Install new parts where necessary. Locks with defects can cause the valve to slide 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 sending oil to the cylinder head.

3. Too Much Valve Lash

Make adjustment. See the Subject Valve Lash in Testing & Adjusting.

4. Damage To Valves

Make a replacement of the valve(s) 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 core in the engine oil cooler.

2. Defect In Head Gasket

Install a new head gasket.

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 on the crankshaft. Install new parts when necessary.

2. Damage To Timing Gears

Install new parts where necessary.

3. Damage To Crankshaft

Make replacement of the crankshaft.

Problem 12: Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks

Large changes in fuel consumption may be the result. Inspect the fuel system for leaks and make repairs as necessary.

2. Fuel And Combustion Noise (Knock)

Small increases in fuel consumption may be the result of fuel nozzles with defects, rough running, or factors causing loss of power. See Problem 3 and Problem 6:

3. Wrong Fuel Injection Timing

Make an adjustment to fuel injection timing.

Problem 13: Loud Noise From Valves Or Valve Operating Components

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.

3. Damage To Valve Lifter

Clean engine thoroughly. Make a replacement of the camshaft and valve lifters. Look for valves that do not move freely. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

4. Damage To Valve(s)

Make a replacement of the valve(s) and make an adjustment as necessary.

Problem 14: Little Movement Of Rocker Arm And Too Much Valve Lash

Probable Cause:

1. Too Much Valve Lash

Make adjustment. See the Subject Valve Lash in Testing & Adjusting.

2. Not Enough Lubrication

Check lubricant 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 sending oil to the cylinder head.

3. Rocker Arm Worn At Face That Makes Contact With Valve

If there is too much wear, install new rocker arms. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

4. End Of Valve Stem Worn

If there is too much wear, install new valves. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

5. Worn Push Rods

If there is too much wear, install new push rods. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

6. Valve Lifters Worn

If there is too much wear, install new valve lifters. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

7. Damage To Valve Lifters

Install new valve lifters. Check camshaft for wear. Check for free movement of valves or bent valve stem. Clean engine thoroughly. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

8. Worn Cams On Camshaft

Check valve lash. Check for free movement of valves or bent valve stems. Check for valve lifter wear. Install a new camshaft. Make adjustment of valve lash. See the Subject Valve Lash in Testing & Adjusting.

Problem 15: Valve Rotocoil Or Spring Lock Is Free

Probable Cause:

1. Damage To Locks

Locks with damage can cause the valve to fall into the cylinder. This will cause much damage.

2. Damage To Valve Spring(s)

Install new valve spring(s).

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 that there is a plug in each end.

2. Worn Valve Guides

Reconditioning of the cylinder head is needed.

3. Worn Piston Rings

Worn piston rings and/or cylinder walls can be the cause of blue smoke and can cause a loss of compression. Make a visual inspection of the cylinder walls and piston rings. If necessary, measure the cylinder walls and piston rings. For the cylinder and piston ring specifications, see the Specifications module.

4. Running Engine Too Long At Low Idle

Don't let the engine run for long periods of time at low idle.

Problem 17: Little Or No Valve Lash

Probable Cause:

1. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed. Make an adjustment to valve lash. See the Subject Valve Lash in Testing & Adjusting.

Problem 18: Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil

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

2. Air Inlet Leaks

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

3. Fuel Leakage Into Lubrication Oil

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

Problem 19: Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Engine Oil Cooler Core

Install a new core for the engine oil cooler.

2. Failure Of Cylinder Head Gasket

Install a new cylinder head gasket. Tighten the bolts holding the cylinder head, according to 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. Failure Of Seals For Cylinder Liners

Make a 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. Check inlet manifold pressure. Inspect turbocharger for correct operation.

2. Bad Fuel Injection Nozzle(s)

Test all nozzles. Install new nozzles if test shows replacement is needed.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

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. Do not put too much oil in engine.

2. Misfiring Or Running Rough

Make Reference to Problem 3.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Worn Valve Guides

See the Specifications module for the maximum permissible wear of the valve guides.

5. Worn Piston Rings

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. Defect In Oil Pressure Indicator

Install new indicator.

2. Dirty Engine Oil Filter Or Engine Oil Cooler:

Check the operation of bypass valve for the filter. Install new engine oil filter elements if needed. Clean or install new engine oil cooler core. Remove dirty oil from engine. Put clean oil in engine.

3. 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 engine oil filter element. Put clean oil in the engine.

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

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

5. Oil Pump Suction Pipe Has A Defect

Replacement of pipe is needed.

6. Relief Valve For Oil Pump Does Not Operate Correctly

Clean valve and housing. Install new parts as necessary.

7. Engine Oil Pump Has A Defect

Make repair or replacement of engine oil pump if necessary.

8. Too Much Clearance Between Camshaft And Camshaft Bearings

Install new camshaft and camshaft bearings if necessary.

9. Too Much Clearance Between Crankshaft And Crankshaft Bearings

Inspect bearings and crankshaft journals and make repairs and replacements as necessary.

10. Too Much Bearing Clearance For Idler Gear

Inspect bearings and make replacement as necessary.

11. Orifices For Piston Cooling Not Installed

Install piston cooling jets.

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. Do not put too much 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 Valve Compartment

Make reference to Problem 16.

5. Worn Valve Guides

Make reference to Problem 16.

6. Worn Piston Rings And Cylinder Liners

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 Air Flow Through Radiator Or Restriction To Flow Of Coolant Through The Radiator

Remove all restrictions to flow.

2. Not Enough Coolant In System

Add coolant to cooling system.

3. Pressure Cap Has A Defect

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

4. Combustion Gases In Coolant

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

5. 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.

6. Water Pump Has A Defect

Make repairs to the water pump as necessary.

7. Too Much Load On The System

Make a reduction in the load.

8. 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.

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 bad fuel injection nozzle, 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 retarded.

Fuel System Inspection

To check for low fuel pressure, remove the 1/8" Pipe Plug from the fuel filter base. Connect a pressure indicator from the 6V9450 Engine Pressure Group to the hole where the plug was removed. Run the engine at high idle and check the fuel pressure reading. The fuel pressure must be at least 105 kPa (15 psi).

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 bad bend.

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

4. Remove any air that may be in the fuel system. If there is air in the fuel system, use the priming pump and open the drain valve on the fuel injection pump housing until fuel without air comes from the drain line.

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NOTICE

When fuel injection lines are loosened or tightened on the fuel injection nozzles, two wrenches must be used. The nozzle must be held with a wrench or damage to the nozzle can result.

To remove air from the fuel injection lines, loosen the fuel line nuts on the fuel injection nozzles 1/2 turn. Move the governor lever to the low idle position. Crank engine with the starter motor until fuel without air comes from the fuel line connections. Tighten the fuel line nuts.

NOTE: The fuel priming pump will not give enough pressure to push fuel through the reverse flow check valves in the fuel injection pumps.

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 fuel injection pump and fuel injection nozzle for that cylinder.

Temperature of an exhaust manifold port, when an 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 possible be an indication of a 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 a nozzle with a defect.

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

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

2. Orifice wear.

3. Steel wire brushing of nozzle tip.

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 from the fuel injection pumps goes to the fuel injection nozzles through the fuel injection lines.

When fuel injection lines are disconnected or removed, always put caps or plugs on the ends to keep dirt out of the lines. When fuel injection lines are installed, be sure all clamps and dampers are installed in their original location.

The nuts that hold a fuel injection line to a fuel injection nozzle and fuel 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 5P144 Fuel Line Socket to tighten the fuel injection line nuts to 40 ± 7 N·m (30 ± 5 lb ft)

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Fuel injection lines which are bent, damaged or rubbing can leak and cause a fire. Replace any lines which have damage or leaks that cannot be corrected when tightened to 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
Fig. A. Illustrates the contact surfaces of a new pump plunger and a new lifter. In Fig. B the pump plunger and lifter have worn considerably. Fig. C shows how the flat end of a new plunger makes poor contact with a worn lifter, resulting in rapid wear to both parts.

A fuel 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

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 center position before the fuel injection pumps can be removed.

1. Remove timing pin cover (1) from the side of the fuel injection pump housing.

Fuel Injection Pump Housing
(1) Timing pin cover.

2. Move the governor lever to the Fuel OFF position and install timing pin (2) in the rack centering hole as shown.

Timing Pin Installed
(2) Timing pin.

3. With the timing pin in position, move the governor lever to the high idle position. The fuel rack will move until the edge of the groove in the rack makes contact with the timing pin. The fuel rack is now in the center position. Fasten the governor lever in the HIGH IDLE position.

4. Remove the fuel injection line from the fuel injection pump.

5. Put the 8T5287 Wrench into spline of bushing that holds the fuel injection pump in the housing. Remove the bushing.

6. Install the 8S2244 Extractor on the threads of the injection pump. Carefully pull the pump straight up out of the 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 fuel injection pumps and spacers 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 Pumps

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NOTICE

The fuel rack MUST BE IN THE CENTER POSITION before the correct installation of an injection pump is possible.

Fuel Pump Installation
(3) 8S2244 Extractor. (4) Groove of barrel. (5) Fourth tooth of gear segment.

1. Put the fuel rack in the center position. Make reference to Removal of Fuel Injection Pumps.

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

3. Make sure the lifter for the fuel injection pump to be installed is at the bottom of its travel.

4. Put the groove of barrel (4) in alignment with the middle (fourth) tooth of gear segment (5).

5. Look into the bore for the fuel injection pump and locate both dowels. There is a dowel in the lifter and a dowel in the opposite side of the bore in the fuel injection pump housing. Put the groove in the fuel injection pump barrel in alignment with the large dowel in the fuel injection pump housing and put the slot (groove) on the opposite side of the gear teeth on the sector gear in alignment with the small dowel in the lifter. Install the fuel injection pump straight down into the bore.

6. Push down on extractor (3) (hand force only) and install O-ring and bushing that holds the fuel injection pump in the fuel pump housing. If the fuel injection pump is in the correct position, the bushing will turn into the threads of the fuel injection housing with the fingers until it is even with the top of the fuel injection housing. When the bushing is installed correctly, tighten the bushing to 165 ± 14 N·m (120 ± 10 lb ft)

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NOTICE

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

7. Install the fuel injection line to the fuel injection pump and tighten to 40 ± 7 N·m (30 ± 5 lb ft).

8. Remove timing pin (2) and install timing pin cover (1).

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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, take the precautions (steps) that follow to stop the engine if it starts to overspeed (run out of control).

a. Remove the air cleaner pipe from the turbocharger and leave the air inlet for the turbocharger open.

b. Set the governor at low idle.

Stopping The Engine (Typical Example)

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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 to stop the engine.

Locating Top Center Compression Position For No. 1 Piston

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

NOTE: The engine is seen from the flywheel end when direction of crankshaft rotation is given.

1. Remove starting motor.

2. Install the tools as shown.

Engine Turning Tools Installed
(1) 5P7306 Housing. (2) 5P7305 Gear. (3) Timing bolt.

3. Remove the valve cover.

4. Rotate the crankshaft clockwise approximately 30 degrees. The reason for this step is to be sure the free play is removed from the timing gears when the engine is put on top center.

5. Remove the plug from the timing hole in the flywheel housing. Rotate the crankshaft until a 3/8-16 NC bolt, 50.8 mm (2.00 in) long, can be turned into the flywheel through the timing hole in the flywheel housing. No. 1 piston is now on top center.

Valve Cover Removed
(4) Rocker arms.

NOTE: If the crankshaft is turned beyond top center do Steps 4 and 5 again.

6. The inlet and exhaust valves for No. 1 cylinder will be closed if No. 1 piston is on the compression stroke. You can move the rocker arms up and down with your hand.

7. If No. 1 piston is not on the compression stroke, remove the timing bolt and rotate the crankshaft counterclockwise 360 degrees. Install the timing bolt. The No. 1 piston is now at top center on the compression stroke.

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 technician 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 technician 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. They should then 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
(10) 6V7910 transducer. (13) Fuel injection line (for No. 1 cylinder).

3. Loosen all fuel line clamps that hold No. 1 fuel injection line and disconnect fuel injection line (13) (for No. 1 cylinder) at the fuel injection pump. Slide the nut up and out of the way. Put 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 adapter (9).

4. Put the adapter (11) on the transducer (10) and put the end of the adapter (11) in the "window" of the adapter (9).

5. Put fuel injection line (13) on top of adapter (11). Install adapter (7) and tighten to a torque of not more than 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) 6V2197 magnetic transducer. (5) 6V3093 transducer adapter.

7. Push the magnetic transducer (3) into the transducer adapter (5) until it makes contact with the flywheel. Pull it back out 1.6 mm (.06 in) and lightly tighten the knurled locknut.

8. Connect the cables from the transducer 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.

Make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct timing specifications to use.

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/Adjusting Engine Timing By Timing Pin Method

1. Put No. 1 piston at top center on the compression stroke. Make reference to Locating Top Center Compression Position For No. 1 Piston. Remove the timing bolt and rotate the crankshaft clockwise 30 degrees.

Timing Pin Cover
(1) Timing pin cover. (2) Cover for timing gear. (3) Nut.

2. Remove timing pin cover (1) from the side of the fuel injection pump housing.

Timing Pin Installed
(4) 6V4186 Timing Pin.

3. Install timing pin (4) in the fuel injection pump housing as shown. Slowly rotate the crankshaft counterclockwise until timing pin (4) 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 camshaft or the timing pin.

4. Put the timing bolt in the timing hole in the flywheel housing. Slowly move the crankshaft counterclockwise (as seen from the flywheel end of the engine) until the fuel pump camshaft is tight against timing pin (4). 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 pump is correct.

5. If the timing bolt does no go into the timing hole in the flywheel, the timing of the fuel injection pump is not correct. Do the steps that follow to adjust the fuel injection pump timing.

6. Remove nuts (3) and cover (2) from the timing gear housing.

Timing Gear For Fuel Injection Pump
(5) Bolt.

7. Loosen bolt (5) that holds the timing gear to the fuel pump camshaft. Turn bolt (5) out (counterclockwise) three turns.

8. Install puller group (6) and loosen the timing gear from the fuel pump camshaft.

Puller Tools Installed
(6) 8S2264 Puller Group. (7) 8B7560 Step Plate. (8) 1B3680 Bolt 3/8-24 NF, 95.3 mm (3.75 in) long. (9) 4B5271 Washer.

9. Rotate the flywheel clockwise 60 degrees before top center No. 1 piston.

10. Tighten retaining bolt (5) finger tight. Be sure timing pin (4) is in the groove in the fuel pump camshaft.

11. Slowly rotate the crankshaft counterclockwise until the timing bolt can be installed in the flywheel.

12. Install adapter (10) on the timing gear. Use two 3/8-24 NF bolts, 25.4 mm (1.0 in) long to fasten the adapter to the puller holes in the timing gear.

Adapter Installed On Timing Gear
(10) 6V6175 Adapter.

13. Hold a torque of 60 to 70 N·m (45 to 50 lb ft) on adapter (10) in a clockwise direction, and tighten bolt (5) that holds the timing gear to 270 ± 30 N·m (200 ± 20 lb ft).

14. Remove the timing bolt from the flywheel and timing pin (4) from the fuel pump camshaft.

15. Rotate the crankshaft counterclockwise two revolutions. If the timing bolt can be installed in the flywheel and the timing pin can be installed in the fuel pump camshaft, the timing is correct.

16. If either the timing pin or the timing bolt cannot be installed, do Step 7 through Step 16 again.

Tightening Timing Gear Bolt

Governor Adjustment For Fuel Ratio Control

The governor adjustment for the fuel ratio control can be done with the fuel injection pump and governor on or off the engine.

NOTE: The fuel ratio control is set to specific dimensions at the factory. If the control is disassembled it must be set again on the 6V2029 Fixture Group before the governor adjustment is made. Make reference to Fuel Injection Test Bench SEHS7466 Section IV-Q for instructions for the use of 6V2029 Fixture Group.

Fuel Injection Pump And Governor
(1) Cover.

1. Remove cover (1) from the side of the fuel injection pump housing.

2. Install collet (2) on bracket assembly (3).

3. Install the bracket assembly on the fuel pump housing. Lever (5) on the bracket assembly must be in slot (4) on the fuel rack. Push up on the bracket assembly while the bolts are tightened.

Bracket Assembly Installed
(2) 5P4814 Collet. (3) 6V2014 Bracket Assembly.

Cover Removed
(4) Slot (on fuel rack).

NOTE: After the bracket assembly is tightened to the pump housing, shaft (6) must have axial (in and out) movement. If there is no axial movement of shaft (6), check to be sure lever (5) is in the slot on the fuel rack and that the bracket assembly is installed correctly. Check to make sure that lever (5) is not bent. Lever (5) must be perpendicular (at right angle) to the mounting face of the bracket assembly.

Bracket Assembly
(5) Lever. (6) Shaft.

Dial Indicator Installed
(7) 6V3075 Dial Indicator.

4. Put 9S229 Contact Point, 9.7 mm (.38 in) long on dial indicator (7) and install dial indicator in collet (2).

Governor
(8) Fuel Ratio Control.

Rear Of Governor Housing
(9) Plug.

6. Remove plug (9) from the rear of the governor housing.

7. Move the governor control lever to the fuel off position (rotate governor shaft clockwise).

Timing Pin Installed
(10) 6V4186 Timing Pin.

8. Install timing pin (10) in the hole in the bracket assembly. Push timing pin in until contact is made with the fuel rack. Hold the timing pin gently against the fuel rack for Steps 9 and 10. If too much force is used to hold the timing pin, the fuel rack can stick and cause an incorrect zero reading.

9. Hold the governor control lever in the high idle position (rotate governor shaft counterclockwise).

6V7942 Hook In Use
(11) 6V7942 Hook.

Cutaway View Of Governor
(11) 6V7942 Hook. (12) Collar.

10. Insert hook (11) into the hole that plug (9) was removed from. Engage the end of hook (11) with collar (12) and pull toward the rear of the governor housing until the collar stops moving. This will make sure the fuel rack stops against the timing pin. This is the zack zero position.

11. With the hook still pulled toward the rear of the governor, loosen collet (2) and adjust the revolution counter on the dial indicator to zero. Tighten the collet just enough to hold the indicator in this position. Move the dial of the indicator to get alignment of the pointer and zero.

12. Remove timing pin (10) and hook (11), then release the governor control lever.

6V7941 Compressor Assembly
(13) Rod. (14) Knob.

Compressor Assembly Installed
(15) 6V7941 Compressor Assembly.

13. Turn rod (13) out of the compressor assembly (15) until knob (14) is 25.4 mm (1.0 in) from the compressor body. Install compressor assembly (15) in the hole plug (9) was removed from.

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

14. Move the governor control lever to the fuel off position. Use two S1614 Bolts and install governor adjustment tool (16). Be sure the end of the tool is behind the governor linkage, and that the flange is completely against the governor housing (the filter screen may have to be removed.

NOTE: If it is expected to be necessary to change the setting, install the outer part of 6V2105 Rack Adjustment Tool Group (17) along the left side of the 6V2017 Governor Adjustment Tool when the 6V2017 Governor Adjustment Tool is installed.

Adjusting Tool Installed
(16) 6V2017 Governor Adjustment Tool.

Governor Linkage Adjustment
(17) 6V2105 Rack Adjustment Tool Group.

15. Move the governor control to the full load position and hold in this position.

16. Turn the over fueling spring compressor rod IN (clockwise) until the indicator hands move approximately 1 mm.

17. Slowly turn the rod out (counterclockwise) until the indicator hand stops moving. This is the fuel ratio control setting.

NOTE: There will be a small initial movement of the dial indicator hands, then, they will stop moving while the rod is turned out for 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.

18. Make reference to the fuel setting information for the correct fuel ratio setting and compare to the dial indicator reading.

19. If the fuel ratio control setting is not correct, use rack adjustment tool group (17) to loosen the locknut and turn the adjustment screw (18). Turn the screw clockwise to decrease the amount of fuel possible (less rack travel) at the limited position.

NOTE: One revolution of the adjustment screw will change the setting approximately 0.79 mm (.031 in).

Adjustment Screw For Governor
(18) Adjustment screw.

NOTE: The dial indicator hands will not follow the turning of the adjustment screw. It will be necessary to repeat Steps 15 through 19 until setting is obtained.

Fuel Ratio Control And Governor Check

1. Remove the air line from the fuel ratio control and then remove the fuel ratio control.

Remove Air Line

2. Install the rack position indicator to measure fuel rack movement. See Steps 1 through 4 in the Fuel Setting Procedure for the correct installation of the tooling.

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

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

5. Install the 6V4186 Timing Pin in the rack zeroing hole in the pump housing.

6. With the governor control lever in the full FUEL OFF position, use a 1N9954 lever and move the manual shutoff (if equipped) 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.

7. Release the manual shutoff shaft and zero 8T1000 position indicator (press the zero button).

8. Remove the 6V4186 Timing Pin and watch the indicator movement. The 8T1000 position indicator should show positive reading movement in the FUEL ON direction. If no movement occurs, repeat Steps 5, 6 and 7 to zero the indicator.

9. Release the governor control shaft and linkage.

10. Replace the fuel ratio control but do not reconnect the air line.

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

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

FT1906 Air Test Kit
(1) 8L6557 Connector. (2) 5P4405 Connector (two required). (3) 5P6011 Tube. (4) 5P4476 Connector. (5) 6K5741 Valve. (6) 5P4459 Elbow. (7) 7B192 Cross. (8) 3B6768 Bushing. (9) 6V7775 Indicator. (10) 6N3169 Hose Assembly. (11) 6V6757 Elbow. (12) 6.35 mm (.250 in) I.D. Flexible Tubing [1.2 m (4 ft) long]. (13) Air pressure bulb (Baumamometer No. 1890 or equivalent).

12. 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 the fitting from which the air line was removed.

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 13.

13. From low idle, rapidly move the governor control shaft to the full FUEL ON position and read the measurement on the 8T1000 position indicator. Press the "MAX" on the indicator to read the "dynamic fuel ratio control setting". Record the reading. Repeat three or four times.

NOTE: The fuel ratio control is activated and the maximum reading is the dynamic full torque setting of the engine. This setting is 0.5 mm (.02 in) greater than the static full torque setting. See the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct setting.

NOTE: On engines with the fuel ratio control out of adjustment, the fuel ratio control is active at startup. At this time the 8T1000 position indicator reading can be the dynamic fuel ratio control setting. Continue the checking procedure to find the dynamic full torque setting at Step 17.

14. Release all air pressure from the fuel ratio control. Start at low idle setting (in fuel setting specs) and rapidly move the governor control shaft to the full FUEL ON position and read the measurement on the 8T1000 position indicator. Press the "MAX" on the indicator to read the "dynamic fuel ratio control setting". Record the reading. Repeat three for four times.

15. If the dynamic fuel ratio setting is within ± 0.25 mm (.010 in) of the specifications in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche, an adjustment is not necessary.

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

17. Check boost pressure that gives full torque rack travel, as follows:

a. Connect a pressure indicator, a pressure regulator and an air supply to the fitting from which the air line was removed.

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 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 13.

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: 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 and make reference to the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche for the correct dynamic fuel ratio control setting specification before and adjustment is made.

2. Remove the air fuel ratio control.

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

4. Remove the cover from the fuel ratio control valve.

Fuel Ratio Control (Typical Example)
(1) Nut. (2) Extension.

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

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

6. Hold extension (2) in position and loosen nut (1). This keeps the fuel ratio diaphragm from turning when nut (1) is loosened or tightened.

7. Turn extension (2) to get the correct setting. A clockwise direction will give a more positive setting. The counterclockwise direction will give a more negative setting. Several adjustments of extension (2) may be needed to get the correct dynamic fuel ratio control setting.

8. After each adjustment is made, check the dynamic fuel ratio control setting. Start at low idle setting (in fuel setting specs) and rapidly move the governor control shaft to the full FUEL ON position. Press the "MAX" on the indicator to read the "dynamic fuel ratio control setting". Record the reading. Repeat three or four times.

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.

9. After the correct adjustment has been made, tighten nut (1). Check the dynamic fuel ratio control setting again.

10. Install the O-ring and cover on the fuel ratio control. Tighten the bolts to a torque of 9 ± 3 N·m (80 ± 26 lb in).

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

12. Check the dynamic full torque setting. Start at low idle setting (in fuel setting specs) 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.

13. Stop the engine.

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

15. Install the air line on the engine.

16. Remove the rack position indicator tooling.

Fuel Setting Procedure

The static fuel setting can be done with the fuel injection pump and governor on or off the engine. For more information on the fuel setting procedure, see Special Instruction, SEHS8024.

Fuel Injection Pump And Governor
(1) Cover.

1. Remove the fuel filter base and fuel line from the fuel injection pump housing and remove cover (1) from the side of the fuel injection pump housing.

Bracket Assembly Installed
(2) 5P4814 Collet. (3) Bracket assembly.

2. Install collet (2) on bracket assembly (3).

Cover Removed
(4) Slot (on fuel rack).

3. Install the bracket assembly on the fuel pump housing. Lever (5) on the bracket assembly must be in slot (4) on the fuel rack. Push up on the bracket assembly while the bolts are tightened.

Bracket Assembly
(5) Lever. (6) Shaft.

After the bracket assembly is tightened to the pump housing, shaft (6) must have axial (in and out) movement, If there is no axial movement of shaft (6), check to be sure lever (5) is in the slot on the fuel rack and that the bracket assembly is installed correctly. Check to make sure that lever (5) is not bent. Lever (5) must be perpendicular (at right angle) to the mounting face of the bracket assembly.

Dial Indicator Installed
(7) 6V3075 Dial Indicator.

4. Put 9S229 Contact Point, 9.7 mm (.38 in) long on dial indicator (7) and install dial indicator (7) in collet (2).

Governor
(8) Fuel Ratio Control

5. Remove fuel ratio control (8), (or cover), from the rear of the governor housing.

Rear Of Governor Housing
(9) Plug.

6. Remove plug (9) from the rear of the governor housing.

7. Move the governor control lever to the FUEL OFF position (rotate governor shaft clockwise).

Timing Pin Installed
(10) 6V4186

6V7942 Hook In Use
(11) 6V7942 Hook.

Cutaway View Of Governor
(11) 6V7942 Hook. (12) Collar.

9. Hold the governor control lever in the HIGH IDLE position (rotate governor shaft counterclockwise).

12. Remove timing pin (10).

6V7941 Compressor Assembly
(13) Rod. (14) Knob.

Compressor Assembly Installed
(15) 6V7941 Compressor Assembly.

13. Turn rod (13) out of compressor assembly (15) until knob (14) is 25.4 mm (1.0 in) from the compressor body. Install compressor assembly (15) in the hole plug (9) was removed from.

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

The procedure to check the fuel setting is different than the procedure to adjust the fuel setting. Follow Steps 14 through 17 to check the fuel setting. Follow Steps 18 through 21 to adjust the fuel setting.

Checking Static Fuel Setting
(16) 8T500 Circuit Tester. (17) Rack contact screw. (18) Adjustment screw cover.

14. Fasten the clip end of circuit tester (16) to rack contact screw (17) and put the other end to a good electrical ground.

15. Hold the governor control lever in the FUEL ON position (rotate lever fully counterclockwise).

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

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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.

17. Slowly turn rod (13) OUT (counterclockwise) until the circuit tester light just comes on. This is the STATIC FUEL SETTING. See the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche for the correct static fuel setting.

NOTE: When the rod is turned OUT, there will 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.

18. If the fuel setting is not correct, remove adjustment screw cover (18) from the rear of the governor housing.

Adjustment Screw Cover Removed
(19) Adjustment screw.

19. Determine how much the setting will have to be changed (see example). Use the chart that follows to determine how far the adjustment screw must be turned.

Since "desired setting" is higher than "actual reading," turn adjustment 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 adjustment 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 adjustment 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 adjustment 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 adjustment screw in approximately 27/8 turns.

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

Adjusting Fuel Setting
(20) 6V2105 Rack Adjustment Tool Group.

20. Use 6V2105 Rack Adjustment Tool Group (20) to loosen the locknut for adjustment screw and to turn the adjustment screw.

21. Adjust the fuel setting screw the number of turns determined in Step 19. Always recheck the setting after each adjustment and adjust again if needed.

Engine Speed Measurement

9U7400 Multitach II Group

The 9U7400 Multitach II Group can measure engine speed from a tachometer drive on the engine. It also has the ability to measure engine speed from visual engine parts in rotation.

Operators Manual, NEHS0605 is with the 9U7400 Multitach II 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 9U7400 Multitach II Group. 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 ± rpm.

6V4950 Injection Line Speed Pickup Group

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 service technician 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 Measuring Engine Speed.

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) Cover. (2) Low idle screw.

1. To adjust the LOW IDLE rpm, start the engine and run with the governor in the low idle position. Loosen the locknut for low idle screw (2). 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 9U7400 Multitach II Group can be used to check the set point. Operators Manual, NEHS0605 gives instructions for installation and use of this tool group.

9U7400 Multitach II Group

Alternate Method

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 and 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.

Terminal Location
(3) Brass terminal screw.

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

2. Connect the clip end of the 8T500 Circuit Tester to the brass terminal screw (3) on the governor housing. Hold 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 5 and 7 with the information 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 ± 30 rpm. If the readings from Steps 5 and 7 are within the tolerance, no adjustment is needed.

NOTE: It is possible in some applications that the high idle rpm will be less than the 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 (1) and loosen locknut. Turn adjustment screw (4) to adjust the set point to the midpoint of the tolerance.

3. 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.

Set Point Adjustment
(4) Adjustment screw.

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 Screw Adjustment

The dashpot adjustment screw does not normally need adjustment from the factory setting. If the engine is slow to change rpm with a change in load, it is possible that the dashpot adjustment screw is not adjusted correctly.

1. Turn dashpot adjustment screw (5) in (clockwise) until it stops.

2. Turn dashpot adjustment screw out (counterclockwise) 1/2 ± 1/4 turn.

Dashpot Screw Adjustment
(5) Dashpot adjustment screw.

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 of more than 7.5 kPa (30 inches of H₂O) difference in pressure.

Back pressure from the exhaust (pressure difference measurement between exhaust outlet elbow and atmosphere) must not be more than 6.7 kPa (27 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.

A difference 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.

Location For Pressure Test
(A) Remove plug and install a tee for testing.

1U5470 Engine Pressure Group

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

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.

Checking Aftercooler Operation

4C6500 Digital Thermometer Group

Use the 4C6500 Digital Thermometer to check the operation of the aftercooler. The testing procedure is in Operating Manual, NEHS0554.

Air To Air Aftercooler System

Visual Inspection

Inspect all air lines, hoses and gasket connections at each oil change. Make sure the constant torque hose clamps are tight. Check welded joints for cracks and make sure all brackets are tightened in position and are in good condition. Use compressed air to clean aftercooler core blockage caused by debris or dust. Inspect the aftercooler core fins for damage or debris.

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Pressure air can cause personal injury.

When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes.

NOTE: When air to air aftercooler system parts are repaired and/or replaced, a leak test is recommended.

Air System Restriction

Pressure measurements should be taken at the turbocharger outlet and inlet manifold. When the total pressure drop of the charged air system at maximum air flow exceeds 13.5 kPa (4 in Hg), the air lines and cooler core must be inspected for internal restriction and cleaned, repaired or replaced as necessary.

Turbocharger Failure

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Pressure air can cause personal injury.
When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes.

The maximum air pressure must be below 205 kPa (30 psi) for cleaning purposes.

If a turbocharger failure occurs, remove the air to air aftercooler core and flush internally with a solvent that removes oil and other foreign substances. Shake aftercooler to eliminate any trapped debris. Wash with hot, soapy water; rinse thoroughly with clean water; and blow dry with compressed air in reverse direction of normal air flow. Carefully inspect the system to make sure it is clean.

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NOTICE

Do not use caustic cleaners or damage to the aftercooler core will result.

Inlet Manifold Pressure

Normal inlet manifold pressure with high exhaust temperature can be caused by aftercooler core fin blockage. Clean the aftercooler core fins, see Visual Inspection for the cleaning procedure to use.

Low inlet manifold pressure and high exhaust manifold temperature can be caused by any of the conditions that follow:

1. A plugged air cleaner. Clean or replace the air cleaner as needed.

2. A blockage in the air lines between the air cleaner and turbocharger. All restrictions must be removed.

3. Aftercooler core leakage. Pressure test the cooler core, see Aftercooler Core Leakage for the correct procedure to use and repair or replace parts as needed.

4. Leakage from the pressure side of the induction system. Check and repair leaks.

5. Inlet air leak. Check for loose, missing and damaged fittings or plugs. Also check the air inlet to cylinder head gaskets.

Aftercooler Core Leakage

FT1984 Air to Air Aftercooler Test Group
(1) Coupler. (2) Chain. (3) Dust plugs. (4) Nipple. (5) Regulator and valve assembly. (6) Tee. (7) Relief valve.

A low power problem in the engine can be the result of aftercooler leakage. Low power, low boost pressure, black smoke, and/or high exhaust temperature can be the result of an aftercooler system leakage.

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NOTICE

Remove all air leaks from the system to prevent engine damage. In some operating conditions, the engine can pull a manifold vacuum for short periods of time. A leak in the aftercooler or air lines can let dirt and other foreign material into the engine and cause rapid wear and/or damage to engine parts.

A large cooler core leak often can be found by making a visual inspection. To check for smaller leaks, use the following procedure:

1. Disconnect the air pipes from the inlet and outlet side of the aftercooler core.

Air To Air Aftercooler
(8) Aftercooler. (9) Aftercooler air inlet.

2. Install couplers (1) and dust plugs (3) from the FT1984 Air to Air Aftercooler Test Group as shown on each side of the aftercooler core. Installation of additional hose clamps on hump hoses is recommended to prevent the hoses from bulging while the aftercooler core is being pressurized.

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Dust plug chains (2) must be installed to the aftercooler core or the radiator brackets to prevent possible injury while testing. Do not stand in front of the dust plugs while testing.

Air To Air Aftercooler
(10) Air outlet. (11) Cylinder head.

3. Install regulator and valve assembly (5) on the outlet side of the aftercooler. Attach air supply.

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NOTICE

Do not use more than 240 kPa (35 psi) air pressure or damage to the aftercooler core can be the result.

4. Open air valve and pressurize the aftercooler to 205 kPa (30 psi). Shut off air supply.

5. Inspect all connections for air leakage.

6. System pressure should not drop more than 35 kPa (5 psi) in 15 seconds.

7. If the pressure drop is more than specified, use a solution of soap and water to check all areas of possible leakage and look for air bubbles. Replace hoses or repair the aftercooler core as needed.

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To help prevent personal injury when the tooling is removed, relieve all pressure in the system slowly by using air regulator and valve assembly (5).

8. After testing, remove FT Tooling and connect air pipes on each side of the aftercooler.

Dynamometer Test

Air to air aftercooled dynamometer tests, in hot ambient temperatures, can add a greater heat load to the jacket water cooling system, therefore the jacket water cooling system temperature must be monitored. Also, monitor the inlet air temperature as it may need a power correction factor along with fuel API, fuel temperature and barometric pressure.

For engine dynamometer tests, use the FT1438 Dynamometer Testing Aftercooler. FT1438 provides an air to water aftercooler to control the inlet air temperature to 43°C (110°F).

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 it 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.

Refer to the Specifications for the correct end play dimensions. 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 buildup on the turbine wheel and should be disassembled for cleaning and inspection.

Checking Turbocharger Rotating Assembly End Play (Typical Example)

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

Crankcase (Crankshaft Compartment) Pressure

Pistons or piston rings that have damage can be the cause of too much pressure in the crankcase. This condition will cause the engine to run rough. There will also be more than the normal amount of fumes coming from the crankcase breather. This crankcase pressure can also cause the element for the crankcase breather to have a restriction in a very short time. It can also be the cause of oil leakage at gaskets and seals that would not normally have leakage.

Normal crankcase pressure with a clean crankcase breather is .5 kPa (2 inches H₂O).

Exhaust Temperature

Use the 123-6700 Infrared Thermometer Group to check exhaust temperature. The Operator's Manual, NEHS0630, for the 123-6700 Infrared Thermometer gives complete operating and maintenance instructions for this tool.

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Use the test that follows for a fast and easy method to find a cylinder that has low compression, or does not have good fuel combustion. Find the speed that the engine runs the roughest, and keep the engine at this rpm until the test is finished. Loosen a fuel line nut at fuel injection pump to 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. This test can also be an indication that the fuel injection is wrong, so the cylinder will have to be checked thoroughly.

Cylinder Head

The cylinder head has valves, valve seat inserts, and valve guides 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 valve seat inserts are in the 6V4805 Valve Insert Puller Group. Special Instruction, SMHS7935 gives an explanation for this procedure. The insert can be more easily installed by lowering the temperature of the insert before installing it in the head.

Valve Guides

Tools needed to install valve guides are: 7S8858 Driver Bushing and 9U7349 Driver. The counterbore in the driver bushing installs the guide to the correct height. Use a 1P7451 Honing Arrangement to make a finished bore in the valve guide after installing the guide in the head. Special Instruction, SMHS7526 gives an explanation of this procedure. Grind the valves after installing new valve guides.

Checking Valve Guide Bore

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.

5P3536 Valve Guide Gauge Group

Valve Lash

NOTE: Valve lash is measured between the rocker arm and 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

Cylinder And Valve Identification

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 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.

3. 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.

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

5. After valve adjustment is correct, tighten the nuts for the valve adjustment screws to 28 ± 4 N·m (22 ± 3 lb ft).

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

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 an indicator to read oil pressure in the engine. Special Instruction, SEHS8524 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 either SAE 10W30 oil. If any other viscosity of oil is used, the information in the engine oil pressure chart does not apply.

2. Remove oil pressure switch (1) and connect the 1U5470 Engine Pressure Group to the main oil manifold at the location from which the oil pressure switch was removed.

Oil Pressure Switch Location
(1) Oil pressure switch.

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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. Run the engine to get the engine oil temperature at 99°C (210°F).

NOTE: A 3°C (5°F) increase in temperature gives approximately 7 kPa (1 psi) decrease in engine oil pressure.

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

4. Keep the engine oil temperature constant. With the engine at the rpm from the chart, read the pressure indicator. On the Engine Oil Pressure Graph find the point that the lines for the engine rpm and oil pressure intersect (connect).

5. 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, 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 cannot get to a maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter Bypass Valve

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 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.

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

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the oil pump cannot 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. A broken oil passage can also be the cause.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it cannot 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 the 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 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 amount 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 pressure cap and/or 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.

Boiling Point Of Water

Test Tools for Cooling System

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 Special Instruction, NEHS0554.

4C6500 Digital Thermometer 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.

8T2700 Blowby/Air Flow Indicator Group

The 9U7400 Multitach II Group is used to check the fan speed. The testing procedure is in Operators Manual, NEHS0605.

9U7400 Multitach II Group

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

9S8140 Cooling System Pressurizing Pump Group

Checking Pressure Cap

One cause for a pressure loss in the cooling system can be a bad 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 moved.

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

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.

5. If the pressure cap is bad, 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 cap or pressure cap on a hot engine. Steam or hot coolant can cause severe burns.

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

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. Get the pressure reading on the indicator to 20 kPa (3 psi) more than the pressure 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.

Water Temperature Regulator

1. Remove the regulator from the engine.

2. Heat water in a pan until the temperature is 90°C (195°F). This is the correct temperature for opening the regulator. Move the water around in the pan to make it all be 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 Keystone Piston Ring Groove 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 Keystone Piston Ring Groove Gauge Group

Pistons With Straight Sides in Ring Grooves

A 5P3519 Piston Ring Groove Gauge is available for checking ring grooves with straight sides. For instructions on the use of the gauge, see the Guideline For Reusable Parts; Pistons, SEBF8049.

Piston Ring Groove Gauge

Connecting Rods And Pistons

Use the 7S9470 Piston Ring Expander to remove or install piston rings.

Use the 5P3525 Piston Ring Compressor to install pistons into cylinder block.

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

1. Put 4C5593 Anti-Seize Compound on threads.

2. Tighten both nuts to 40 ± 4 N·m (30 ± 3 lb ft).

3. Put a mark on each nut and cap.

4. Tighten each nut 90 degrees from the mark.

The connecting rod bearings must fit tightly in the bore in the rod. If bearing joints or backs are worn (fretted), check for bore size as this is an indication of wear because of looseness.

Connecting Rod And Main Bearings

Bearings are available with 0.25 mm (.010 in), 0.51 mm (.020 in) and 0.76 mm (.030 in) smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller) than the original size.

Cylinder Liner Projection

(1) Bolt. (2) Washer. (3) Washer.

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

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

NOTE: Install the plastic washer next to the spacer plate.

3. Use the 8T0455 Liner Projection Tool Group to measure liner projection at positions indicated with 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.

4. The cylinder liner specifications are as follows:

Liner projection ... 0.033 to 0.175 mm (0.0013 to 0.0069 in)

Maximum variation in each cylinder ... 0.051 mm (.0020 in)

Maximum average variation between adjacent cylinders ... 0.051 mm (.0020 in)

Maximum variation between all cylinders ... 0.102 mm (.0040 in)

5. 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.

NOTE: Do not exceed the maximum liner projection of 0.152 mm (.0060 in). Excessive liner projection will contribute to liner flange cracking.

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

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

If the lower O-rings are black in color, apply liquid soap on the lower O-ring seals and the cylinder block. Use clean engine oil on the upper filler band.

If the lower O-rings are brown in color, apply engine oil on the lower O-ring seals, the cylinder block, and the upper filler band.

NOTE: Apply liquid soap and/or clean engine oil immediately before assembly. If applied too early, the filler bands may swell and be pinched under the liners during installation.

Cylinder Block

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts holding the caps to the torque shown in the Specifications Section of this service manual. Alignment error in the bores must not be more than 0.08 mm (.003 in). Special Instruction, SMHS7606 gives instructions for checking alignment of the main bearing bores. 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction, GMG00981 is with the group.

1P3537 Dial Bore Gauge Group

Flywheel And Flywheel Housing

Installing Ring Gear

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 (Typical Example)

Checking Face Runout Of The Flywheel Housing

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" (zero) 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

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.

8T5096 Dial Indicator Group Installed (Typical Example)

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 1 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 (Typical Example)

2. Set the dial indicator to read "0" (zero).

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 (Typical Example)
(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" (zero).

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 bore runout (radial eccentricity) of the flywheel.

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed 0.13 mm (.005 in).

Checking Flywheel Clutch Pilot Bearing Bore