Introduction

NOTE: For Specifications with illustrations, make reference to Specifications for 3208 Industrial & Marine Engines, SENR4606. If the Specifications in SENR4606 are not the same as in 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. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.

This list of problems, causes and corrections, will only given an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.

1. Engine Will Not Start.

2. Misfiring Or Running Rough.

3. Stall At Low rpm.

4. Sudden Changes In Engine rpm.

5. Not Enough Power.

6. Too Much Vibration.

7. Loud Combustion Noise.

8. Loud Noise (Clicking) From Valve Compartment.

9. Oil In Cooling System.

10. Mechanical Noise (Knock) In Engine.

11. Fuel Consumption Too High.

12. Loud Noise From Valves Or Valve Drive Components.

13. Little Movement Of Rocker Arm And Too Much Valve Lash.

14. Valve Spring Lock Is Free.

15. Oil At The Exhaust.

16. Little Or No Valve Lash.

17. Engine Has Early Wear.

18. Coolant In Lubrication Oil.

19. Too Much Black Or Gray Smoke.

20. Too Much White Or Blue Smoke.

21. Engine Has Low Oil Pressure.

22. Engine Uses Too Much Lubrication Oil.

23. Engine Coolant Is Too Hot.

24. Starting Motor Does Not Turn.

25. Alternator Gives No Charge.

26. Alternator Charge Rate Is Low Or Not Regulator.

27. Alternator Charge Is Too High.

28. Alternator Has Noise.

29. Exhaust Temperature Is Too High.

Problem 1. Engine Will Not Start

Probable Cause:

1. Empty Fuel Tank

Put fuel in fuel tank.

2. Poor Quality Fuel

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

3. Dirty Fuel Filter

Install new fuel filter.

4. Dirty Or Broken Fuel Lines

Clean or install new fuel lines as necessary.

5. Linkage To Sleeve Control Shaft Is Held In Shutoff Position

Check the operation of the shutoff solenoid and the shutoff linkage. Solenoid must pull up to compress spring for fuel turn on. Check governor linkage for free movement. Sleeves must turn freely on fuel injection pump plungers in all positions of sleeve control shaft. The thrust collar must turn freely on the governor shaft at all positions between shutoff and full load. If linkage does not move freely under these conditions, clean all parts thoroughly. Inspect all parts for wear and make replacement where needed.

6. Fuel Pressure Is Too Low

Replace the fuel filter. Inspect the bypass valve for free movement. Install a new bypass valve if necessary.

7. Air In The Fuel System

Find the air leak in the fuel system and correct it. Remove air from the fuel system. Make reference to Removing Air From Fuel System in Testing & Adjusting.

8. Fuel System Not Timed Correctly To Engine

Make adjustment to timing if necessary.

9. Constant Purge Valve Stays Open (not enough fuel pressure for starting)

Replace constant purge valve.

10. No Overfuel Spring

Install an overfuel spring.

11. Fuel Ratio Control Has A Defect

Check fuel ratio control setting. Adjust if necessary. Check operation of solenoid.

Problem 2. Misfiring Or Running Rough

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is enough fuel in the fuel tank. Look for leaks or severe bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 205 ± 35 kPa (30 ± 5 psi). If fuel pressure is lower than above pressure, install a new fuel filter element. Inspect the fuel bypass valve for free movement. Install a new fuel bypass valve if necessary.

2. Air In The Fuel System

Find the air leak in the fuel system and correct it. Remove air from the fuel system. Make reference to Removing Air From Fuel System in Testing & Adjusting.

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

Install a new fuel injection line.

4. Wrong Valve Lash

Make adjustment according to Testing & Adjusting.

5. Defect In Fuel Injection Nozzle

Run engine at rpm that gives maximum misfiring or rough running. Then loosen a fuel line nut on the fuel injection line 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 nozzle for that cylinder. Install new parts where needed.

6. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 3. Stall At Low RPM

Probable Cause:

1. Fuel Pressure Is Low

Make sure there is enough fuel in the fuel tank. Look for leaks or severe bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 205 ± 35 kPa (30 ± 5 psi). If fuel pressure is lower than above pressure, install a new fuel filter element. Inspect the bypass valve for free movement. Install a new bypass valve if necessary.

2. Idle rpm Too Low

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

3. Defect In Fuel Injection Nozzle

Install a new fuel injection nozzle.

4. Wrong Valve Lash

Make adjustment according to Testing & Adjusting.

5. Spring For Dashpot Governor Installed Wrong

Install spring correctly.

Problem 4. Sudden Changes In Engine RPM

Probable Cause:

1. Air In the Fuel System

Find the air leak in the fuel system and correct it. Remove air from the fuel system. Make reference to Removing Air From Fuel System in Testing & Adjusting.

2. Broken Torsion Spring On Sleeve Control Shaft

Install new parts as needed.

3. Linkage In Governor Does Not Move Freely

Clean all linkage and inside of governor housing. Install new parts for those parts that have damage.

4. Governor Springs Not Completely On Spring Seat

Put springs completely on spring seat.

5. Spring For Dashpot Governor Installed Wrong

Install spring correctly

Problem 5. Not Enough Power

Probable Cause:

1. Poor Quality Fuel

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

2. Fuel Pressure Is Low

Make sure there is fuel in the fuel tank. Look for leaks or severe bends in the fuel line between fuel tank and fuel transfer pump. Look for air in the fuel system. Check fuel pressure. The outlet pressure of the fuel transfer pump at full load speed is 205 ± 35 kPa (30 ± 5 psi).

If fuel pressure is lower than above pressure, install a new fuel filter element. Inspect the fuel bypass valve for free movement. Install a new fuel bypass valve if necessary.

3. Air In The Fuel System

Find the air leak in the fuel system and correct it. Remove air from the fuel system. Make reference to Removing Air From Fuel System in Testing & Adjusting.

4. Leaks In Air Inlet System

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

5. Wrong Fuel Setting

Make adjustments as necessary.

6. Governor Linkage

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

7. Defect In Timing Advance Unit

Replacement of timing advance unit is needed.

8. Wrong Valve Lash

Make adjustment according to Testing & Adjusting.

9. Defect In Fuel Injection Nozzle

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

10. Wrong Fuel Injection Timing

Make adjusting to timing.

11. Fuel Shutoff Solenoid or Shutoff Linkage Causing A Restriction In The Travel Of The Shaft For The Sleeves

Check for correct full power with solenoid removed. If the engine has full power with the solenoid removed, the problem is in the solenoid or the shutoff linkage. Check for free travel of the linkage.

12. Constant Purge Stays Closed

Replace constant purge valve.

13. Turbocharger Has Carbon Deposit

Inspect and repair turbocharger as necessary.

14. Fuel Ratio Control Has A Defect

Check fuel ratio control setting. Adjust if necessary. Check diaphragm in fuel ratio control.

Problem 6. Too Much Vibration

Probable Cause:

1. Loose Bolt Or Nut Holding Pulley Or Damper

Tighten bolt or nut.

2. Pulley Or Damper Has A Defect

Install a new pulley or damper.

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

Tighten all mounting bolts. Install new components if necessary.

4. Misfiring Or Running Rough

Make Reference to Item 2.

Problem 7. Loud Combustion Noise (Sound)

Probable Cause:

1. Poor Quality Fuel

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

2. Defect In Fuel Injection Nozzle.

Install a new fuel injection nozzle.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

Problem 8. Loud Noise (Clicking) From Valve Compartment

Probable Cause:

1. Broken Valve Spring(s) Or Locks

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

2. Loose Bolts Holding Rocker Arm Assembly

Tighten to 24 ± 7 N·m (18 ± 5 lb ft).

3. Too Much Valve Lash

Make adjustment according to Testing & Adjusting.

Problem 9. Oil In Cooling System

Probable Cause:

1. Defect In Core Of Oil Cooler

Install a new core in the oil cooler.

2. Defect In Head Gasket

Install a new head gasket.

Problem 10. 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 where necessary.

2. Damage To Crankshaft

Make replacement of the crankshaft.

3. Defect In Attachment

Repair or install new components.

Problem 11. Fuel Consumption Too High

Probable Cause:

1. Fuel System Leaks

Replacement of parts is needed at points of leakage.

2. Defect In Timing Advance Unit

Replacement of timing advance unit is needed.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Fuel Setting Too High

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

Problem 12. Loud Noise From Valve Or Valve Drive Components

Probable Cause:

1. Broken Valve Spring(s)

Make replacement of parts with damage.

2. Broken Camshaft

Make replacement of parts with damage. Clean engine thoroughly.

3. Broken Timing Advance Gear

Make replacement of timing advance unit.

Problem 13. Little Movement Of Rocker Arm And Too Much Valve Lash

Probable Cause:

1. Not Enough Lubrication

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

2. Rocker Arm Parts Worn

If there is too much wear, install new parts or rocker arms. Make adjustment of valve lash according to Testing & Adjusting.

3. End Of Valve Stem Worn

If there is too much wear, install new valves. Make adjustment of valve lash according to Testing & Adjusting.

4. Too Much Valve Lash

Make adjustment according to Testing & Adjusting.

5. Worn Push Rods

If there is too much wear, install new push rods, Make adjustment of valve lash according to Testing & Adjusting.

6. Camshaft Lifters Worn

If there is too much wear, install new camshaft lifters. Make adjustment of valve lash according to Testing & Adjusting.

7. Worn Lobes On Camshaft

Check valve lash. Check for free movement of valves or bent valve stems. Install new components as necessary. Make adjustment of valve lash according to Testing & Adjusting.

8. Loose Bolts Holding Rocker Arm Assembly

Tighten to 24 ± 7 N·m (18 ± 5 lb ft).

Problem 14. Valve Spring Lock Is Free

Probable Cause:

1. Broken Locks

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

2. Broken Valve Spring(s)

Install new valve spring(s).

Problem 15. 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

Inspect and install new parts as needed.

Problem 16. Little Or No Valve Lash

Probable Cause

1. Worn Valve Seat Or Face Of Valve

Reconditioning of cylinder head is needed. Make adjustment of valve lash according to Testing & Adjusting.

Problem 17. Engine Has Early Wear

Probable Cause:

1. Dirt In Lubrication Oil

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

2. Air Inlet Leaks

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

3. Fuel Leakage Into Lubrication Oil

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

Problem 18. Coolant In Lubrication Oil

Probable Cause:

1. Failure Of Oil Cooler Core

Install a new core for the oil cooler.

2. Failure Of Cylinder Head Gasket

Install a new cylinder head gasket. Tighten the bolts holding the cylinder head, according to the Specifications.

3. Crack Or Defect In Cylinder Head

Install a new cylinder head.

4. Crack Or Defect In Cylinder Block

Install a new cylinder block.

5. Failure Of Front Cover Gasket

Install a new front cover gasket.

Problem 19. Too Much Black Or Gray Smoke

Probable Cause:

1. Not Enough Air For Combustion

Check air cleaner to restrictions [Max. 635 mm (25 in) of water].

2. Defective Fuel Injection Nozzle(s)

Install new fuel injection nozzle(s).

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Fuel Ratio Control Has A Defect

Check fuel ratio control setting. Adjust if necessary. Check for broken springs.

Problem 20. 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 2.

3. Wrong Fuel Injection Timing

Make adjustment to timing.

4. Worn Valve Guides

Reconditioning of cylinder head is needed.

5. Worn Piston Rings

Install new parts as necessary.

6. Defect In Timing Advance Unit

Replacement of timing advance unit is needed.

7. Failure Of Turbocharger Oil Seal

Check air inlet pipes for oil. Repair turbocharger if necessary.

Problem 21. Engine Has Low Oil Pressure

Probable Cause:

1. Defect In Oil Pressure Gauge

Install new gauge.

2. Dirty Oil Filter Or Oil Cooler

Check the operation of bypass valve for the filter. Install new oil filter elements if needed. Clean or install new 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 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. Oil Pump Has A Defect

Make repair or replacement of oil pump if necessary.

8. Too Much Clearance Between Crankshaft And Crankshaft Bearings

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

9. Too Much Clearance Between Camshaft And Camshaft Bearings

Install new camshaft and camshaft bearings if necessary.

Problem 22. 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 oil cooler. Install new parts if necessary. Clean the core of the oil cooler. Check oil cooler bypass valve.

4. Too Much Oil To Inlet Valve Guides

Make reference to Problem 15.

5. Worn Valve Guides

Make reference to Problem 15.

6. Worn Piston Rings

Install new parts as necessary.

7. Failure Of Turbocharger Oil Seal

Inspect turbocharger and repair if necessary.

Problem 23. Engine Coolant Is Too Hot

Probable Cause:

1. Restriction To Air Flow Through Radiator Or Restriction To Flow Of Coolant Through The Heat Exchanger

Remove all restrictions of flow.

2. Not Enough Coolant In System

Add coolant to cooling system.

3. Pressure Cap Has A Defect

Check operations 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 Regulators Or Temperature Gauge Has A Defect

Check water temperature regulators for correct operation. Check temperature gauge operation. Install new parts as necessary.

6. Water Pump Has A Defect

Install a new water pump.

7. Too Much Load On The System

Make a reduction to the load.

8. Wrong Fuel Injection Timing

Make adjustment to timing.

9. Shunt Line Has A Defect

Make repairs as needed.

10. Drive Belts Loose

Adjust drive belts.

Problem 24. Starting Motor Does Not Turn

Probable Cause:

1. Battery Has Low Output

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

2. Wiring Or Switch Has A Defect

Make repairs or replacement as necessary.

3. Starting Motor Solenoid Has A Defect

Install a new solenoid.

4. Starting Motor Has A Defect

Make repair or replacement of starting motor.

Problem 25. Alternator Give No Charge

Probable Cause:

1. Loose Drive Belt For Alternator

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

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

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts that have a defect.

3. Alternator Brushes (if equipped) Have A Defect

Install new brushes.

4. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 26. Alternator Charge Rate Is Low Or Not Regular

Probable Cause:

1. Loose Drive Belt For Alternator

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

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

Inspect all cables and connections. Clean and tighten all connections. Make replacement of parts that have a defect.

3. Alternator Regulator Has A Defect

Make repair or replacement of alternator regulator.

4. Alternator Brushes (if equipped) Have A Defect

Install new brushes.

5. Rectifier Diodes Have A Defect

Make replacement of rectifier diode that has a defect.

6. Rotor (Field Coil) Has A Defect

Install a new rotor.

Problem 27. Alternator Charge Too High

Probable Cause:

1. Alternator Or Alternator Regulator Has Loose Connections

Tighten all connections to alternator or alternator regulator.

2. Alternator Regulator Has A Defect

Install a new alternator regulator.

Problem 28. Alternator Has Noise

Probable Cause:

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

Install a new drive belt for the alternator.

2. Loose Alternator Drive Pulley

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

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

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

4. Worn Alternator Bearings.

Install new bearings in the alternator.

Problem 29. 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.

3. Air Inlet System Has A Leak

Check pressure in inlet system. Find leaks and correct.

4. Exhaust System Has A Leak

Find cause of exhaust leak and correct.

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 valve, 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.

Fuel System Inspection

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

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

2. Check the fuel injection 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 fuel screen located in the inlet valve of the fuel transfer pump.

4. Remove any air that may be in the fuel system. Open the drain valve on the fuel injection pump housing. Operate the fuel priming pump until fuel without air comes from the drain lines. Close the drain valve.

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

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

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

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

2. Orifice wear.

3. Dirty nozzle screen.

Testing Fuel Injection Nozzles

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

Each fuel injection line of an engine has a special design and must be installed in a certain location. When fuel injection lines are removed from an engine, put identification marks or tags on the fuel lines as they are removed, so they can be put in the correct location when they are installed.

6N0037 Nut (For use with 7000 series nozzle).

Engines with "Pencil-Type" fuel injection nozzles use fuel injection lines which have 6.35 mm (.250 in) outside diameters, 1.60 mm (.063 in) inside diameters, and use a 5M7418 Nut. Engines with "7000 series" fuel injection nozzles use fuel injection lines which have 6.35 mm (.250 in) outside diameters, 1.83 mm (.072 in) inside diameters and use a 6N0037 Nut. The "7000 Series" fuel injection lines appear to be identical to the fuel injection lines of the "Pencil-Type" fuel injection nozzles. However, they are not interchangeable because of the difference in the inside diameter and can be identified by the notch in the nuts on the "7000 Series" fuel injection lines. The fuel injection lines for "Pencil-Type" fuel injection nozzles do not have notches on the nuts.

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 5P0144 Fuel Line Socket to tighten the fuel injection line nuts to 40 ± 7 N·m (30 ± 5 lb ft).

Fuel Injection Pumps

When fuel injection pumps, sleeves and lifters are removed from the fuel injection pump housing, keep the parts of each fuel injection pump together so they can be installed back in their original location.

Be careful when disassembling fuel injection pumps. Do not damage the surface on the plunger. The plunger, sleeve and barrel for each fuel injection pump are made as a set. Do not put the plunger of one fuel injection pump in the barrel or sleeve of another pump. If one part is worn, install a complete new fuel injection pump assembly. Be careful when putting the plunger in the bore of the barrel or sleeve.

When a fuel injection pump is installed correctly, the plunger is through the sleeve and the adjustment lever is engaged with the groove on the sleeve. The bushing that holds the fuel injection pump in the fuel injection pump housing must be kept tight. Tighten the bushing to 80 ± 7 N·m (60 ± 5 lb ft). Damage to the fuel injection pump housing will result if the bushing is too tight. If the bushing is not tight enough, the fuel injection pump will leak.

Air Inlet Pipe

Show/hide table

NOTICE
If the sleeves on one or more of the fuel injection pumps have been installed wrong, damage to the engine is possible if cautions are not taken at first starting. When the fuel injection pumps have been removed and installed with the fuel injection pump housing on engine, take the cautions that follow to stop the engine, if it starts to overspeed (run out of control).

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

b. Set the governor control at low idle.

Show/hide table

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

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

Stopping The Engine

Finding Top Center Compression Position For No. 1 Piston

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

Fitting And Bolt Location
(1) Fitting. (2) Bolt.

Installing Bolt
(2) Bolt. (3) Timing hole.

1. Remove fitting (1) from the timing hole (3) in the front cover. Put bolt (2) in timing hole (3).

2. Turn the crankshaft Counterclockwise (when viewed from the rear of engine) until bolt (2) will go into the hole in the drive gear for the camshaft.

3. Remove the valve cover on the right side of the engine (when viewed from the rear of engine). The two valves at the right front of the engine are the inlet and exhaust valves for No. 1 cylinder.

4. The inlet and exhaust valves for No. 1 cylinder must now be closed and the timing pointer will be in alignment with the TC-1 on the damper assembly. The No. 1 piston is now at top center on the compression stroke.

Fuel System Adjustments

Checking Fuel Injection Pump Timing; On Engine

The timing of the fuel injection pump can be checked and changed if necessary, to make compensation for movement in the taper sleeve drive or worn timing gears. The timing can be checked and if necessary, changed using the following method.

Checking Timing By Timing Pin Method

Timing Hole Bolt
(1) Bolt.

1. Remove bolt (1) from the timing pin hole.

Timing Pin Installed
(2) 3P1544 Timing Pin.

Installing Bolt
(3) 1D4539 Bolt, 5/16 in- 18 NC, 63.5 mm (2.50 in) long. (4) Timing hole. (5) Hole.

2. Turn the crankshaft Counterclockwise (as viewed from rear of engine) until timing pin (2) goes into the notch in the camshaft for the fuel injection pumps.

3. Remove the fitting from timing hole (4) in the front cover. Put bolt (3) through the front cover and into the hole with threads in the timing gear. The bolt from hole (5) can be used.

4. If the timing pin is in the notch in the camshaft for the fuel injection pumps, and bolt (3) goes into the hole in the timing gear through timing hole (4), the timing of the fuel injection pump is correct.

NOTE: If bolt (3) does not go in the hole in the timing gear with timing pin (2) in the notch in the camshaft, use the procedure that follows.

Location Of Cover
(6) Cover for the tachometer drive assembly. (7) Nuts.

a. Remove nuts (7) and the cover for the tachometer drive assembly (6).

b. Remove the tachometer drive shaft (9) and washer (8) from the camshaft for the fuel injection pumps.

NOTE: Tachometer drive shaft (9) and washer (8) are removed as an assembly.

Location Of Bolt
(8) Washer. (9) Tachometer drive shaft.

Loosening Drive Gear
(10) 6V4069 Puller. (11) Bolts.

c. Put 6V4069 Puller (10) on the camshaft for the fuel injection pumps. Tighten bolts (11) until the drive gear on the camshaft for the fuel injection pumps comes loose.

d. Remove the 6V4069 Puller.

e. Turn the crankshaft Counterclockwise (as viewed from rear of engine) until bolt (3) goes into the hole in the timing gear. With timing pin (2) in the notch in the camshaft for the fuel injection pumps, and bolt (3) in the hole in the timing gear, the timing for the engine is correct.

f. Install washer (8) and tachometer drive shaft (9). Tighten tachometer drive shaft to 149 ± 14 N·m (110 ± 10 lb ft). Remove timing pin (2).

g. Turn the crankshaft two complete revolutions Counterclockwise (as viewed from rear of engine) and put timing pin (2) and bolt (3) in again. If timing pin (2) and bolt (3) can not be installed do Steps a through f again.

h. Remove bolt (3) from the timing gear and install in hole (5). Install the plug in timing hole (4). Remove timing pin (2) and install bolt (1). Install cover for the tachometer drive assembly (6).

Checking Engine Timing And Automatic Timing Advance Unit 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 & 6V3093 Transducer Adapters. (6) 8K4644 Fuse.

The 8T5300 Timing Indicator Group must be used with an 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, Caterpillar recommends that the service technician calculate and plot the dynamic timing specifications first 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. For the correct timing specifications to use, see the Engine Information Plate for the performance specification number and make reference to the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche.

NOTE: For more information on acceptable tolerances for dynamic fuel injection timing, see Service Magazine dated 4-1-85 and 10-28-85.

After the timing values are calculated and plotted, the dynamic timing should be checked with the 8T5300 Engine Timing Indicator Group and the 8T5301 Diesel Timing Adapter Group. The engine must be operated from 1000 rpm (base rpm) and from high idle to 1000 rpm (base rpm). Unstable readings are often obtained below 1000 rpm. Record the dynamic timing at each 100 rpm and at the specified speeds during both acceleration and deceleration. Then he should plot the results on the worksheet.

Inspection of the plotted values will show if the fuel injection timing is within specifications.

Transducer In Position
(10) Injection transducer. (13) Fuel injection line for No. 1 cylinder.

1. Make reference to Special Instruction SEHS8580 for complete service information and use of 8T5300 Timing Indicator Group.

2. 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 5P7436 Adapter (9) in its place and turn adapter (9) onto the fuel injection pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in the adapter.

3. Put the 5P7435 Adapter (11) on 6V7910 Transducer (10) and put the end of the 5P7435 Adapter (11) in the "window" of the 5P7436 Adapter (9).

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

Location Of Fitting
(14) Fitting.

5. Remove fitting (14) from the front housing. Install transducer adapter (5) into hole fitting (14) was removed from. Tighten only a small amount.

Transducer In Position
(3) TC magnetic transducer.

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

7. Connect the cables from the transducers to the Engine Timing Indicator. Make a calibration check of the indicator. For calibration procedure, make reference to Special Instruction SEHS8580.

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NOTICE
Be sure all test equipment cables are routed so they will not come into contact with the belts or other rotating components.

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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.

8. 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.

9. Run the engine at the speeds required to check low idle, timing advance and high idle. Record the engine timing indicator readings. If the engine timing is not correct, make reference to Fuel System Adjustments: On Engine, Fuel Injection Pump Timing (Timing Pin Method) for static adjustment of the fuel injection pump drive.

10. If the timing advance is still not correct, or if the operation of the advance is not smooth, make a repair or replacement of the automatic advance unit. There is no adjustment to the unit.

Fuel Setting

The procedure that follows for fuel setting can be done with the fuel injection pump housing either on or off the engine.

NOTE: If the fuel injection pump group is equipped with a fuel ratio control, the fuel ratio control must be removed before the fuel setting is checked or adjusted.

NOTE: If a fuel temperature compensated torque control group is used, the temperature of the fuel must be less than 52°C (125°F) when checking or adjusting the fuel setting.

Removal Of Covers
(1) Shutoff solenoid. (2) Top cover.

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NOTICE
Before any service work is done on this fuel system, the outside of the fuel injection pump housing for the fuel injection pumps and all parts connected to it must be clean.

1. Remove shutoff solenoid (1) and top cover (2).

Installation Of Cover
(3) 5P6602 Adapter. (4) 3J6956 Spring. (5) 5P0298 Zero Set Pin, (with 17.8507 on it).

2. Put the 5P0298 Zero Set Pin (5), in the fuel injection pump housing.

3. Put 5P6602 Adapter (3) and 3J6956 Spring (4) over 5P0298 Zero Set Pin (5). Use a 1D4533 Bolt and a 1D4538 Bolt to fasten 5P6602 Adapter (3) to the fuel injection pump housing.

Installation Of 8S7271 Setscrew
(6) 8S7271 Setscrew.

4. Put 8S7271 Screw (6) in the hole over 5P0298 Zero Set Pin (5) and 3J6956 Spring (4).

5. Turn 8S7271 Screw (6) clockwise until 5P0298 Zero Set Pin (5) is held against the fuel injection pump housing. Do Not tighten 8S7271 Setscrew (6) too tight.

Installation Of Clamp
(3) 5P6602 Adapter. (7) 3P1565 Collet Clamp.

6. Put 3P1565 Collet Clamp (7) in 5P6602 Adapter (3).

7. Move the governor control lever to Full Load position.

Installation Of 3P1567 Dial Indicator
(7) 3P1565 Collet Clamp. (8) 3P1567 Dial Indicator. (9) 5P6531 Contact Point, 57.2 mm (2.25 in) long.

8. Put 5P6531 Contact Point (9) on 3P1567 Dial Indicator (8). Put the indicator assembly in 3P1565 Collet Clamp (7).

Indicator Set On Zero
(8) 3P1567 Dial Indicator. (10) Pointers.

9. Adjust 3P1567 Dial Indicator (8) so both pointers (10) are on "0" (zero).

Loosening 8S7271 Setscrew
(11) 5P4205 Wrench.

10. Use 5P4205 Wrench (11) to turn the 8S7271 8S7271 Setscrew (6) counterclockwise. Turn 8S7271 Setscrew (6) six or more turns.

8T0500 Circuit Tester

11. Put the clip end of the 8T0500 Circuit Tester to a good ground. Put the other end of the 8T0500 Circuit Tester on the load stop contact.

12. Move the governor control lever to the Low Idle position.

13. Move the governor control lever slowly toward the High IDLE position until the continuity light just comes on. Make a note of the reading on dial indicator (8). Do this step several times to make sure the reading is correct.

14. Make a comparison of this reading and the fuel setting in the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche.

15. If the reading on 3P1567 Dial Indicator (8) is not correct, do the following.

Load Stop Adjustment

Adjustment Of Fuel Setting
(16) Screwdriver. (17) Adjustment screw. (18) Wrench.

Adjustment Screw For Fuel Setting
(17) Adjustment screw. (19) Locknut. (20) Load stop pin.

Leaf Type Torque Spring

a. Write down the dimension that is on 3P1567 Dial Indicator (8).

b. Write down the dimension given in the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche.

c. Remove the test tools [5P6602 Adapter (3), 3J6956 Spring (4), and 3P1567 Dial Indicator (8)] from the fuel injection pump housing.

Leaf Type Torque Spring
(12) Shims. (13) Stop bar. (14) Leaf type torque spring. (15) Load stop pin.

d. Install or remove shims (12) to get the correct dimension as given in the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche. The difference between the dimensions in (a) and (b) is the thickness and amount of shims to remove or install to get the correct setting.

e. Install the correct amount of shims (12), torque spring (14), and stop bar (13) on the fuel injection pump housing.

f. Install the test tools and do the test procedure again. Do this until the dimension on 3P1567 Dial Indicator is the same as the dimension given in the TMI (Technical Marketing Information) or the Fuel Setting And Related Information Fiche. After the fuel setting is correct, remove the test tools. Install cover (2) and shutoff solenoid.

Crossover Levers

Checking Crossover Levers

NOTE: The crossover levers normally do not need checking unless one or more of the following conditions exist (after the timing is checked and the other corrections shown in Troubleshooting have been made):

A. The engine produces too much black smoke.

B. The engine runs rough because fuel delivery is not even.

C. Some cylinders continue to fire at fuel shutoff position.

D. The complete injection group is being reconditioned.

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NOTICE
Before any service work is done on this fuel system, the outside of the fuel injection pump housing and all parts connected to it must be clean.

Removal Of Covers
(1) Shutoff solenoid. (2) Top cover.

1. Remove the fuel shutoff solenoid (1), top cover (2) of the fuel injection pump housing and the cover over the torque control group.

2. Remove the fuel that is in the fuel injection pump housing and the governor housing.

Installing Calibration Pin
(3) 3P1546 Calibration Pin (with 15.9410 on it).

3. Put the 3P1546 Calibration Pin (3) in calibration hole as shown.

Installing 5P6602 Adapter And 8S7271 Screw
(4) 8S7271 Screw. (5) 5P6602 Adapter.

4. Install the 5P6602 Adapter (5). Fasten it in position with the orginal bolts.

5. Put the 8S7271 Screw (4) (setscrew) in the hole over the 3P1546 Calibration Pin (3). Tighten the 8S7271 Screw (4) to 2.3 to 2.8 N·m (20 to 25 lb in) with the 2P8264 Socket.

Adjustment Of Low Idle Screw
(6) Low idle screw. (7) Lever.

6. Adjust low idle screw (6) to position lever (7) to 8.9 ± 1.0 mm (.35 ± .04 in) from governor housing boss.

Crossover Levers
(8) Crossover lever. (9) Crossover lever. (10) Dowel pin. (A) Sleeve levers.

7. Loosen the bolts that hold sleeve levers (A) and slide sleeve levers (A) out of the way.

Installing 5P4209 Gauge
(11) 5P4209 Gauge. (12) Shaft. (13) Shaft.

8. Put 5P4209 Gauge (11) on shafts (12) and (13). Slide 5P4209 Gauge (11) toward crossover levers (8) and (9) until dowel pin (10) goes into hole in 5P4209 Gauge (11).

9. If dowel pin (10) must be lifted to go into the hole in 5P4209 Gauge (11), the levers must be adjusted. See Adjustment Of Crossover Levers.

10. If 5P4209 Gauge (11) must be lifted more than 0.20 mm (.008 in) to let dowel pin (10) go into the hole in 5P4209 Gauge (11), see Adjustment Of Crossover Levers.

Checking Clearance Of Crossover Lever
(11) 5P4209 Gauge. (14) Feeler gauge.

11. To check the maximum clearance of 0.20 mm (.008 in) that is acceptable under one side of 5P4209 Gauge (11), hold the center and one side of 5P4209 Gauge (11) against sleeve lever shaft (13). Use feeler gauge (14) to check clearance.

NOTE: After the checking of the crossover levers is complete, the two fuel injection pumps must be calibrated where sleeve levers have been moved to install 5P4209 Gauge. See Fuel Injection Pump Calibration.

Adjustment Of Crossover Levers

1. Remove the fuel shutoff solenoid (1) top cover (2) of the fuel injection pump housing and the cover over the torque control group.

2. Remove the fuel that is in the fuel injection pump housing and the governor housing.

3. Put the 3P1546 Calibration Pin (3) in calibration hole.

4. Install the 5P6602 Adapter (5) or the 145-1853 Calibration Fixture. Fasten it in position with original bolts.

5. Put the 8S7271 Screw (4) in the hole over the 3P1546 Calibration Pin (3). Tighten the 8S7271 Screw (4) to 2.3 to 2.8 N·m (20 to 25 lb in) with the 2P8264 Socket.

6. Adjust low idle screw (6) to position lever (7) to 8.9 ± 1.0 mm (.35 ± .04 in) from governor housing boss.

Crossover Levers
(8) Crossover lever. (9) Crossover lever. (10) Dowel pin. (A) Sleeve levers.

7. Loosen the bolts that hold sleeve levers (A) and slide sleeve levers (A) out of the way.

5P4209 Gauge Installed
(9) Crossover lever. (10) Dowel pin. (11) 5P4209 Gauge.

8. Loosen the bolts that hold crossover levers (8) and (9) and move crossover lever (8) off dowel pin (10).

Adjustment Of Crossover Levers
(11) 5P4209 Gauge. (12) Shaft. (13) Shaft. (14) 5P4206 Wrench.

9. Put 5P4209 Gauge (11) on shafts (12) and (13), put crossover lever (9) in a position so dowel pin (10) will fit in gauge hole. Hold 5P4209 Gauge (11) down and torque the bolt that holds crossover lever (9) to 2.8 ± 0.2 N·m (24 ± 2 lb in).

10. Check adjustment again with the 5P4209 gauge (11). Put 5P4209 Gauge (11) on shafts (12 and 13), slide 5P4209 Gauge toward crossover lever (9) to engage dowel pin (10) into hole in 5P4209 Gauge (11).

Tightening Bolt
(8) Crossover lever. (10) Dowel pin. (14) 5P4206 Wrench.

11. If dowel pin (10) must be lifted to go into 5P4209 Gauge, the lever must be adjusted again. If 5P4209 Gauge (11) is lifted, a maximum of 0.20 mm (.008 in) clearance is acceptable under one side of 5P4209 Gauge (11). Use a feeler gauge to check clearance.

12. Slide crossover lever (8) on to dowel pin (10). Torque the bolt that holds crossover lever (8) to 2.8 ± 0.2 N·m (24 ± 2 lb in).

13. Check the adjustment again with the 5P4209 Gauge.

NOTE: After the adjustment of the crossover levers is completed, all of the fuel injection pumps must be calibrated. See Fuel Injection Pump Calibration.

Fuel Injection Pump Calibration

3P2200 Tool Group
(1) 3P1540 Calibration Pump. (2) 7W8120 Bushing. (3) 1P7379 Microgauge. (4) 3P1568 Dial Indicator (with 3P2226 Collet). (5) 5P6510 Box. (6) 3P1545 Calibration Pin (with 17.3734 on it), (In-line engines). (7) 3P1546 Calibration Pin (with 15.9410 on it), (Vee engines). (8) 1S9836 Wrench. A 146-1853 Hex Key (ball) is required for engine adjustment on aftercooled engines.

Checking Fuel Injection Pump Calibration

The following procedure for fuel injection pump calibration can be done with the fuel injection pump housing on or off the engine.

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NOTICE
Before any service work is done on this fuel system, the outside of the fuel injection pump housing and all parts connected to it must be clean.

Removal Of Covers
(9) Shutoff solenoid. (10) Top cover.

1. Remove the fuel shutoff solenoid (9), top cover (1) of the fuel injection pump housing and the cover over the torque control group.

2. Remove the fuel that is in the fuel injection pump housing and the governor housing.

Installing Calibration Pin
(7) 3P1546 Calibration Pin (with 15.9410 on it).

3. Install 3P1546 Calibration Pin (7) in the calibration hole.

Installing 5P6602 Adapter And 8S7271 Screw
(11) 8S7271 Screw. (12) 1D4533 Bolt. (13) 5P6602 Adapter. (14) 1D4538 Bolt.

4. Install 5P6602 Adapter (13) as shown. Fasten it in position on the fuel injection pump housing with a 1D4533 Bolt (12) and a 1D4538 Bolt (14).

5. Put 8S7271 Screw (11) in the hole over 3P1546 Calibration Pin (7). Tighten 8S7271 Screw (11) to 2.3 to 2.8 N·m (20 to 25 lb in).

Adjustment Of Low Idle Screw
(15) Low idle screw. (16) Lever.

6. Adjust low idle screw (15) to position lever (16) to 8.9 ± 1.0 mm (.35 ± .04 in) from governor housing boss.

7. Use the 8S2243 Wrench and remove the fuel injection pumps to be checked.

NOTE: If a fuel injection pump is removed carefully, the sleeve will remain on the pump plunger. If the sleeve falls off the pump plunger during removal, find it immediately and replace it on the pump plunger before removal of another fuel injection pump. The original sleeve must remain with the same pump plunger.

NOTE: When sleeve is installed on pump plunger, the narrower of the two lands on the sleeve must be toward top of fuel injection pump (nearest the pump spring).

Installing 3P1540 Calibration Pump
(1) 3P1540 Calibration Pump.

8. Clean the barrel and plunger of 3P1540 Calibration Pump (1). Put clean diesel fuel on the 3P1540 Calibration Pump (1) for lubrication.

3P1540 Calibration Pump Springs
(1) 5P6557 Spring. (2) 1P7377 Spring.

NOTE: Be sure that the 3P1540 Calibration Pump (1) is the 5P6557 Spring instead of the 1P7377 Spring which was installed on earlier calibration pumps.

Calibration Pump Installed
(1) 3P1540 Calibration Pump. (17) Tang (on lever). (18) Lever. (19) Groove of calibration pump. (20) Flat on plunger.

9. Put 3P1540 Calibration Pump (1) in the place of the fuel injection pump to be checked with the flat place (20) on the plunger toward tang (17) on lever (18). When the 3P1540 Calibration Pump (1) is all the way in the bore, turn it 180 degrees in either clockwise or counterclockwise direction. Tang (17) on lever (18) is now in groove (19) of 3P1540 Calibration Pump (1). Then install 7W8120 Bushing (2). Use the 8S2243 Wrench and a torque wrench to tighten the 7W8120 Bushing (2) to 80 ± 7 N·m (60 ± 5 lb ft).

NOTE: Turning 3P1540 Calibration Pump (1) 180 degrees gives the same reference point for all measurements.

NOTE: Use 7W8120 Bushing (2) and 3P1540 Calibration Pump (1) together. The contact surfaces of the standard bushing, fuel injection pump and the fuel injection pump housing are sealing surfaces. Keep them clean and free of scratches to prevent leaks.

Putting Dial Indicator On Zero
(3) 1P7379 Microgauge. (4) 3P1568 Dial Indicator (with 3P2226 Collet). (21) Lockscrew. (22) Locknut. (23) 3P2226 Collet.

10. Put 3P1568 Dial Indicator (4) on 1P7379 Microgauge (3) and hold them together tightly. Loosen lockscrew (21) and turn the face of 3P1568 Dial Indicator (4) to put the pointer at "0". Tighten lockscrew (21).

Remove 3P1568 Dial Indicator (4) from 1P7379 Microgauge (3). Look at the face of 3P1568 Dial Indicator (4) and put 3P1568 Dial Indicator (4) on 1P7379 Microgauge (3) again. The pointer must move through one to one and one half revolutions before stopping at exactly "0". If the number of revolutions is not correct, loosen the locknut on 3P2226 Collet (23), and adjust the position of the 3P1568 Dial Indicator until the adjustment is correct.

NOTE: If locknut (22) on the 3P2226 Collet is too tight, it can cause interference in the operation of the 3P1568 Dial Indicator (4).

6V0190 Clamp Installed
(24) Shaft. (25) 6V0190 Clamp.

11. Put 6V0190 Clamp (25) in the position shown, next to the transfer pump end. 6V0190 Clamp (25) pushes shaft (24) down against the bottom of its bearing. The other end of shaft (24) is held down against its bearing by 3P1546 Calibration Pin (7) which is held by 8S7271 Screw (11).

The combination of forces from 6V0190 Clamp (25) and 3P1546 Calibration Pin (7) is necessary to hold shaft (24) is in its normal operating position against the lifting force from the spring in 3P1540 Calibration Pump (1).

Dial Indicator Position
(4) 3P1568 Dial Indicator (with 3P2226 Collet). (25) Clamp.

NOTE: When checking fuel injection pumps on the "slave" side [side opposite from governor control lever (16)], put clamp (25) on both ends of sleeve shaft as shown.

12. Put 3P1568 Dial Indicator (4) on the 3P1540 Calibration Pump (1) as shown. Hold it tightly in place. Move shaft (24) toward the governor end to remove end play. To remove any clearance in the linkage, lift the crossover lever dowel and rapidly let it go. Do this several times. Then look at the reading on the 3P1568 Dial Indicator (4).

Installing Clamp On "Slave" Side
(25) 6V0190 Clamps.

13. If the 3P1568 Dial Indicator (4) reading is more than ± 0.050 mm from "0.000" (outside the Total Tolerance), do Steps 17 through 20, Adjusting Fuel Pump Calibration.

3P1568 Dial Indicator Reading
Desired reading for all fuel injection pumps is "0.000".

NOTE: Maximum permissible tolerance for fuel injection pump readings in any Fuel Injection Pump Group is 0.100 mm (-0.050 to +0.050 mm on dial indicator).

NOTE: Maximum permissible differences between any two fuel injection pumps in the same Fuel Injection Pump Group is 0.050 mm.

NOTE: Total Tolerance shows the maximum permissible range of pointer positions which are acceptable. If any reading is outside the range of Total Tolerance, do Adjusting Fuel Injection Pump Calibration for all injection pumps.

NOTE: Band is an example only. It shows a 0.050 mm range. This range shows the maximum permissible difference between any two readings for all the fuel injection pumps. If any two readings are farther apart than the 0.050 mm range, do Adjusting Fuel Injection Pump Calibration for all fuel injection pumps.

If the 3P1568 Dial Indicator (4) reading is near either end of the Total Tolerance, check another pump. If the next reading is outside the Total Tolerance or if the two readings have a difference of 0.050 mm or more, do Steps 15 through 19, Adjustment Of Fuel Injection Pump Calibration.

NOTE: The service technician doing the checking must make the decisions of which and how many fuel injection pumps to check according to the symptoms of the fuel injection pump being tested.

14. If 3P1568 Dial Indicator (4) readings for all the fuel injection pumps are within the limits in Step 13, the calibration is acceptable. Remove the tooling, and install the parts which were removed.

NOTE: For troubleshooting purposes, if the 3P1568 Dial Indicator (4) reading is "0" or near "0", the calibration of the other fuel injection pumps is probably in the tolerance.

Adjustment Of Fuel Injection Pump Calibration

5P4206 Wrench
(18) Lever. (26) Bolt. (A) 5P4206 Wrench.

Plunger Position
(1) 3P1540 Calibration Pump. (27) Top surface (of 3P1540 Calibration Pump). (28) Plunger.

15. Remove all fuel injection pumps with 8S2243 Wrench.

16. Clean the barrel and pump of 3P1540 Calibration Pump (1). Put clean diesel fuel on the 3P1540 Calibration Pump (1) for lubrication.

17. Install 3P1540 Calibration Pump (1) in the place of one of the fuel injection pumps according to the procedure in Step 9.

18. Loosen bolt (26) with 1S9836 Wrench (8) or 5P4206 Wrench. Turn the lever (18) on shaft (24) enough to move the top of plunger (28) of 3P1540 Calibration Pump (1) below top surface (27) (of 3P1540 Calibration Pump). Tighten bolt (26) just enough for lever (18) to hold plunger (28) stationary.

NOTE: When bolt (26) has the correct torque, pushing with a small amount of force on lever (18) through the wrench moves plunger (28) in 3P1540 Calibration Pump (1).

19. Move shaft (24) toward the governor to remove end play. Then push down on lever (18) through the wrench until top of plunger (28) is almost even with top surface (27) (of 3P1540 Calibration Pump) as shown.

20. Check 3P1568 Dial Indicator (4) according to Step 10. Then put 3P1568 Dial Indicator (4) in place over the center of 3P1540 Calibration Pump (1) and hold it there tightly. Now move plunger (28) of 3P1540 Calibration Pump (1) by pushing on lever (18) through the wrench. Stop moving the plunger when the 3P1568 Dial Indicator (4) is at approximately 0.009 mm past "0.000". Tighten bolt (26) to 2.70 ± 0.25 N·m (24 ± 2 lb in).

NOTE: When moving plunger (28), make sure that the last direction of plunger (28) movement is in the up direction. If plunger (28) goes up too far, move plunger (28) down to a position below that desired. Then move plunger (28) up to the desired position.

NOTE: The action of tightening bolt (26) usually changes the reading on 3P1568 Dial Indicator (4) by approximately (0.010 mm) in the minus direction.

± 0.010 mm Calibration Tolerance

Move shaft (24) toward shutoff several times to remove clearance in the linkage. 3P1568 Dial indicator (4) reading must be (0.000 ± 0.010 mm) as shown.

When the fuel injection pump calibration is correct make a record and then do the same procedure for all the other pumps.

Installing Clamp On "Slave" Side
(25) 6V0190 Clamps.

NOTE: When calibrating fuel injection pumps on the "slave" side [side opposite from governor control lever (16)], put clamp (25) on both ends of the sleeve shaft as shown.

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 (balance point) rpm.

Engine rpm must be checked with an accurate tachometer.

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:

Adjustment Of Low Idle RPM
(1) Adjustment bolt for low idle. (2) Locknut.

Adjustment Of Low Idle RPM
(1) Adjustment bolt for low idle. (2) Locknut. (3) Cover.

To adjust the Low Idle rpm, start the engine and run with the governor in the low idle position. Loosen locknut (2) for adjustment bolt for low idle (1). Turn the low idle screw to get the correct low idle rpm. Increase engine speed and return to low idle and check low idle speed again. Tighten the locknut.

Checking Set Point (Balance Point)

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the set point. Refer to Operator's Manual, NEHS0605, for the operating instructions for this tool.

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".

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
(4) Brass terminal screw.

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

2. Connect the clip end of the 8T0500 Circuit Tester to the brass terminal screw (4) on the governor housing. Connect the other end of the tester to a place on the fuel system which is a good ground connection.

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

3. Start the engine.

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

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

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

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

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

9. Stop the engine. Make a comparison of the records from Steps 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) and Fuel Setting And Related Information Fiche. The tolerance for the set point is ± 10 rpm. The tolerance for the high idle rpm is ± 50 rpm. 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.

Adjustment of Set Point
(5) Adjustment screw. (6) Locknut.

2. If the set point rpm is not correct, remove cover (3) and loosen locknut (6). Turn adjustment screw (5) to adjust the set point to the mid point 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.

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.

Engine Speed Measurement

9U7400 Multitach Group

The 9U7400 Multitach Group is used to check the fan speed. Refer to Operator's Manual, NEHS0605, for the operating instructions for this tool.

6V4950 Injection Line Speed Pickup Group

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

Refer to Special Instruction, SEHS8029 for use of the 6V4950 Injection Line Speed Pickup Group.

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 635 mm (25 inches of water) difference in pressure.

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 686 mm (27 inches of water).

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. 747 mm (29.4 inches of mercury) barometric pressure.

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

c. 35 API rated fuel.

Any change from these conditions can change the pressure in the inlet manifold. Outside air that has higher temperature and lower barometric pressure than given above will cause a lower horsepower and a lower inlet manifold pressure measurement than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Outside air that has a lower temperature and a higher barometric pressure will cause higher horsepower and a higher inlet manifold pressure measurement.

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 And Exhaust Do Not Have A Restriction When Making A Check Of Pressure In The Inlet Manifold.

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

1U5470 Engine Pressure Group

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

Location For Pressure Test
(A) Remove fitting and install test fitting.

Location For Pressure Test
(A) Remove fitting and install test fitting.

Turbocharger

Every 7200 hours or 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 excessive end play. The rotating assembly should rotate freely with no rubbing or binding. If there is any indication of the impeller rubbing the compressor cover or the turbine wheel rubbing the turbine housing, recondition the turbocharger or replace with a new or rebuilt one.

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

For the correct end play for the turbochargers see the Specifications Section. If end play is more than the maximum end play rebuild or replace the turbocharger. End play less than the minimum end play could indicate carbon build up on the turbine wheel and 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.

Exhaust Temperature

Use the 123-6700 Infrared Thermometer II to check exhaust temperature. Operator's Manual, NEHS0630 is with the too group and gives instruction for the test procedure.

Cylinder Compression

An engine that runs rough can have a leak at the valves, or valves that need adjustment. Run the engine at the speed that gives rough running. To find a cylinder that has low compression or does not have good fuel ignition, loosen a 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 injection line is found that makes no difference in engine rough running. 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 more checking of the cylinder will be needed.

An analysis of the engine cylinder condition can be done with controlled pressure air through the cylinder head. Special Instruction GMG00694 explains the procedure.

1. Remove the fuel injection nozzle.

2. Adapt an air hose to 1P5564 Adapter. Install the 1P5564 Adapter in the fuel injection nozzle opening in the cylinder head.

3. Start crankshaft rotation until the piston in the cylinder being inspected is at TC on the compression stroke. In this position, the valves of this cylinder will be against their seats.

4. Force the air into the cylinder and then check for air leakage. An air leak from the exhaust opening is an indication of exhaust valve leakage and an air leak from the air cleaner inlet is an indication of inlet valve leakage. If the air leakage is into the crankcase during this test, the piston or piston rings can be the cause.

Valve Lash Setting

Check and adjust the valve lash with engine stopped.

Valve lash is measured with a thickness gauge between the top of the valve stem and the rocker arm.

NOTE: When the valve lash (clearance) 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.

To check and make adjustment to the valve lash, use the procedure that follows:

1. Remove the valve covers.

Cylinder, Valve And Pump Location

2. Turn the crankshaft Counterclockwise (as seen from rear of engine) until No. 1 piston is at top center on the compression stroke. The TC-1 mark on the damper assembly will be in alignment with the timing pointer.

Valve Lash Adjustment
(1) Adjustment screw. (2) Locknut. (3) Feeler gauge.

3. Make adjustment to the valves for No.1 and No.2 cylinders. To make the adjustment, loosen locknut (2). Turn the adjustment screw (1) until the feeler gauge (3) will go between the end of the valve stem and the rocker arm.

4. After the adjustment is complete, hold adjustment screw (1) and tighten locknut (2) to 32 ± 7 N·m (24 ± 5 lb ft). After the locknut is tightened, check the adjustment again.

5. Turn the crankshaft 180 degrees Counterclockwise (as seen from rear of engine). The VS mark on the damper assembly will be in alignment with the timing pointer. Make adjustment to the valves for No.3 and No.7 cylinders.

Tightening Locknut

6. Turn the crankshaft 180 degrees Counterclockwise (as seen from rear of engine). The TC-1 mark on the damper assembly will be in alignment with the timing pointer. Make adjustment to the valves for No.4 and No.5 cylinders.

7. Turn the crankshaft 180 degrees Counterclockwise (as seen from rear of engine). The VS mark on damper assembly will be in alignment with the timing pointer. Make adjustment to the valves for No.6 and No.8 cylinders.

When the adjustment of the valve lash needs to be done several times in a short period of time, it can be an indication of wear in a different part of the engine. Find the problem and make any necessary repairs to prevent more damage to the engine.

Not enough valve lash, if not corrected, can be the cause of rapid wear of the camshaft and lifters. Not enough valve lash can also be an indication of the seats for the valves being defective. Some reasons for the seats for the valves becoming defective are fuel injection nozzles with defects, restrictions to the inlet air or dirty air filters, wrong fuel setting, or using the engine on loads that are too large for the engine.

Too much valve lash, if not corrected, can be the cause for broken valve stems, push rods, or spring retainers. A fast increase in valve lash can be an indication of any of the following:

a. Camshaft and lifters with wear.

b. Rocker arms with wear.

c. Push rods that are bent.

d. Loose adjustment screw for the valve lash.

e. Broken socket on the upper end of the push rod.

If the camshaft and lifters show signs of rapid wear, look for fuel in the lubrication oil or dirty lubrication oil as a possible cause when making the necessary repairs.

Procedure for Measuring Camshaft Lobes

Camshaft Lobe
(A) Lobe lift. (B) Lobe height. (C) Base circle.

To find lobe lift (A) of camshaft, use the procedure that follows:

1. Measure lobe height (B) of one exhaust and one inlet lobe.

2. Measure base circle (C) of one exhaust and one inlet lobe.

3. Subtract base circle (C) dimension (Step 2) from lobe height (B) dimension (Step 1). The difference is actual lobe lift (A).

4. The specified (new) lobe lift (A) is:

(a) Exhaust lobe ... 7.800 mm (.3071 in)

(b) Inlet lobe ... 7.816 mm (.3077 in)

5. The maximum permissible difference between actual lobe lift (Step 3) and specified lobe lift (Step 4) is 0.25 mm (.010 in).

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 ConsumptionOil Pressure Is LowOil Pressure Is HighToo Much Bearing WearIncreased Oil Temperature

Too Much Oil Consumption

Oil Leakage on Outside of Engine

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

Oil Leakage Into Combustion Area of Cylinders

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

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

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

3. Compression ring 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 gauge that has a defect can given an indication of low oil pressure.

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

1U5470 Engine Pressure Group

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

1. Be sure that the engine is filled to the correct level with SAE 10W-30 oil. If any other viscosity of oil is used, the information in the Engine Oil Pressure Graph does not apply.

Oil Pressure Test Location
(A) Oil pressure test location at oil cooler.

Oil Pressure Test Location
(B) Oil pressure test location at rear of right cylinder head.

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

3. Run the engine to get the oil temperature at 93 ± 6°C (200 ± 10°F).

4. Keep the oil temperature constant with the engine at the rated rpm from the chart, and read the pressure gauge.

If the results do not fall within the pressure range given in the chart, 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 pressure outside this range.

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 result in the oil pump not having 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 result in cavitation 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 pressure regulating valve for the system is held in the open (unseated) position, the lubrication system can not get to maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.

Oil Filter and Oil Cooler

A dirty oil filter will cause a reduction in oil pressure. When the oil filter is filled with dirt, a restriction of oil flow through the filter and a reduction of filtered oil pressure is the result.

The bypass valve will cause the flow of oil to go around the filter elements when there is a reduction to the flow through the elements. When the bypass valve is open, oil that is not filtered is permitted to flow through the engine. To correct this problem, install a new Caterpillar filter.

Look for a restriction in the oil passages of the oil cooler. If the oil cooler has a restriction, the oil cooler bypass valve in the oil filter base will open. This will cause the flow of oil to go around the oil cooler. The oil temperature will be higher than normal when the engine is running. The oil pressure of the engine will become low if the oil cooler has a restriction.

Too Much Clearance at Engine Bearings or Open, Broken or Disconnected Oil Line or Passage in Lubrication System

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.

Oil Pressure Is High

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

Too Much Bearing Wear

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

If the gauge for oil pressure shows the correct oil pressure, but a component is worn because it is not getting enough lubrication, look at the passage for oil supply to that 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 and coolant 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 the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (low pressure bubbles suddenly made in liquids by mechanical forces) in the water pump. With this type system, it is more difficult for an air or steam pocket to be made in the cooling system.

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

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

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

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

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

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

Testing The Cooling System

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

Test Tools For Cooling System

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

4C6500 Digitial 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, NEHS8712.

8T2700 Blowby/Air Flow Indicator Group

The 9U7400 Multitach Group is used to check the fan speed. The testing procedure is in Operator's Manual NEHS0605.

9U7400 Multitach Group

Checking Pressure Cap

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

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

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

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

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

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

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

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.

9S8140 Cooling System Pressurizing Pump Group

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

4. Make a comparison of the reading on the gauge 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 defective, install a new pressure cap.

Radiator and Cooling System Leak Tests (Systems That Use Pressure Cap)

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

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

1. 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 gauge 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 gauge is still the same after 5 minutes, the radiator and cooling system do not have leakage. If the reading on the gauge goes down and you do not see any outside leakage, there is leakage on the inside of the cooling system. Make repairs as necessary.

Gauge for Water Temperature

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system can be the cause. If the gauge for water temperature shows that the engine is getting too hot, look for coolant leakage.

If a place can not be found where there is coolant leakage, check the accuracy of the gauge for water temperature. Use the 4C6500 Digitial Thermometer Group. The testing procedure is in Operating Manual NEHS0554.

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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.

Start the engine. Put a cover over part of the radiator. The reading on the gauge for water temperature must be the same as the reading on the thermistor thermometer.

4C6500 Digitial Thermometer Group Installed (Typical Example)

Temperature Regulator

Test procedure for water temperature regulators:

1. Remove the regulator from the engine.

2. Heat a pan of water to the temperature of the regulator being tested. See Specifications.

3. Hang the regulator in the pan of hot water. Put the regulator completely under water. Do not let the regulator make contact with the pan.

4. Keep the temperature of the water constant for ten minutes. Make sure the water moves around. This keeps all of the water at the same temperature.

5. After ten minutes, remove the regulator and immediately measure the distance the regulator is opened. See Specifications for this measurement.

Water Pump Pressure Check

The pressure at the outlet for the water pump tells if the shunt system and water pump are operating correctly. To check the pump pressure, install 6V7775 Pressure Gauge (2) in the front cover. The pressure must be a minimum of 105 kPa (15 psi) at 2800 rpm.

If the pump pressure is less than the minimum pressure: First, check the vent tube between the radiator top tank and the surge tank; it must have an inside diameter of approximately 4.8 mm (.19 in).

Gauge Installed (Typical Example)
(1) 3B7722 Bushing. (2) 6V7775 Pressure Gauge.

Second check to see that the shunt line has a minimum inside diameter of 19.1 mm (.75 in).

Heater Connections

Locations Of Heater Connections

The front housing has several plugs that give access to water passages inside the housing. For the correct access points to install heater hoses, see the preceding photo.

Dynamometer Test Caution

To prevent possible damage to an engine while testing on a dynamometer, the water temperature regulators must be installed and shunt line (2) connected as shown.

Shunt Line Connected To Engine (Typical Example)
(1) FT0790 Cooling Tower Group. (2) Shunt line.

Belt Tension Chart

Basic Block

Connecting Rods And Pistons

Use the 5F9059 Piston Ring Expander to remove or9 install piston rings.

Use the 5P3524 Piston Ring Compressor to install pistons into cylinder block.

Tighten the connecting rod nuts in the following step sequence:

1. Put 2P2506 Thread Lubricant on bolt threads and seating surfaces of cap and nut.

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 60 degrees from the mark.

The connecting rod bearings should 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.

5P3519 Piston Ring Groove Gauge

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.

NOTE: The 5P3519 Piston Ring Groove Gauge is used to check the top ring groove only.

Piston Ring Groove Gauge

Connecting Rod And Main Bearings

Bearings are available with a smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size). Main bearings are available with a larger outside diameter than the original size bearings. These bearings are for cylinder blocks that have had the bore for the main bearings "bored" (made larger than the original size).

Flywheel Runout

Face Runout (Axial Eccentricity) Of The Flywheel:

Checking Face Runout Of The Flywheel

1. Install the 7H1942 Indicator as shown. Put a force on the flywheel toward the rear.

2. Set the 7H1942 Indicator to read 0.00 mm (.000 in).

3. Turn the flywheel and read the 7H1942 Indicator every 90 degrees. Put a force on the flywheel to the rear before each reading.

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

1. Install the 7H1942 Indicator (3) and make an adjustment of the 7H1940 Universal Attachment (4) so it makes contact as shown.

2. Set the 7H1942 Indicator (3) to read 0.00 mm (.000 in).

3. Turn the flywheel and read the 7H1942 Indicator (3) 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.

Checking Flywheel Clutch Pilot Bearing Bore

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

Flywheel Housing Runout

Face Runout (Axial Eccentricity) Of The Flywheel Housing:

8T5096 Dial Indicator Group Installed

1. Fasten the 8T5096 Dial Indicator Group to the crankshaft flange so the anvil of the 7H1942 Indicator will touch the face of the flywheel housing.

2. Put a force on the crankshaft toward the rear before reading the 7H1942 Indicator at each point.

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

3. With the dial of the 8T5096 Dial Indicator Group set at 0.00 mm (.000 in) at location (A), turn the crankshaft and read the 8T5096 Dial Indicator Group at locations (B), (C) and (D).

4. The difference between lower and higher measurements taken at all four points must not be more than 0.25 mm (.010 in), which is the maximum permissible face run out (axial eccentricity) of the flywheel housing.

Flywheel Housing Bore

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

8T5096 Dial Indicator Group Installed

1. With the 7H1942 Indicator in position at (C), adjust the 7H1942 Indicator to "0" (zero). Push the crankshaft up against the top bearing. Write the measurement for bearing clearance on line 1 in column (C).

2. Divide the measurement from Step 1 by 2. Write this number on line 1 in columns (B) & (D).

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

3. Turn the crankshaft to put the 7H1942 Indicator at (A). Adjust the 7H1942 Indicator to "0" (zero).

4. Turn the crankshaft Counterclockwise to put the 7H1942 Indicator at (B). Write the measurement in the chart.

5. Turn the crankshaft Counterclockwise to put the 7H1942 Indicator at (C). Write the measurement in the chart.

6. Turn the crankshaft Counterclockwise to put the 7H1942 Indicator at (D). Write the measurement in the chart.

7. Add lines I and II by columns.

8. 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.

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

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

Total Horizontal Eccentricity

Electrical System

Test Tools For Electrical System

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

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

4C4911 Battery Load Tester

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

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

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

8T0900 AC/DC Clamp-On Ammeter

The 8T0900 AC/DC Clamp-On Ammeter is a completely portable, self-contained instrument that allows electrical current measurements to be made without breaking the circuit or disturbing the insulation on conductors. A digital display is located on the ammeter for reading current directly in a range from 1 to 1200 amperes. If an optional 6V6014 Cable is connected between this ammeter and one of the digital multimeters, current readings of less than 1 ampere can then be read directly from the display of the multimeter.

A lever is used to open the jaws over the conductor [up to a diameter of 19 mm (.75 in)], and the spring loaded jaws are then closed around the conductor for current measurement. A trigger switch that can be locked in the ON or OFF position is used to turn on the ammeter. When the turn-on trigger is released, the last current reading is held on the display for 5 seconds. This allows accurate measurements to be taken in limited access areas where the digital display is not visible to the operator. A zero control is provided for DC operation, and power for the ammeter is supplied by batteries located inside the handle.

NOTE: Make reference to Special Instruction SEHS8420 for more complete information for use of the 8T0900 Clamp-On Ammeter.

6V7070 Heavy-Duty Digital Multimeter

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

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

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

Battery

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

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

Load test a battery that does not hold a charge when in use. To do this, put a resistance across the main connections (terminals) of the battery. For a 6, 8 or 12V battery, use a test load of three times the ampere/hour rating (the maximum test load on any battery is 500 amperes). Let the test load remove the charge (discharge) of the battery for 15 seconds and with the test load still applied, test the battery voltage. A 6V battery in good condition will show 4.5V; and 8V battery will show 6V; a 12V battery will show 9V. Each cell of a battery in good condition must show 1.6V on either a 6, 8 or 12V battery.

Charging System

The condition of charge in the battery at each regular inspection will show if the charging system operates correctly. An adjustment is necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water per cell per week or per every 50 service hours).

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

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

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

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

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

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

Alternator Regulator Adjustment

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

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

Alternator Regulator Adjustment (6N3821)

Alternator Regulator
(1) Adjustment screw. (2) High output position. (3) Green wire to field terminal of alternator. (4) Low output position. (5) Orange wire to field supply terminal.

The regulator components are sealed in an insulation of epoxy. The regulator is an electronic component with no moving parts (solid state) and has an adjustment screw (1) on the back. This voltage adjustment screw is used to meet different needs of operation at different times of the year. To increase or decreases by .5 volts from the normal (N) setting, remove the regulator and change the position of the adjustment screw and pointer. Move adjustment screw (1) and pointer to "H" position (2) to increase the voltage. Move adjustment screw (1) and pointer to "L" position (4) to decrease the voltage.

Alternator Regulator Adjustment (6N3160 and 6N3161)

When the alternator is either charging the battery too much or not enough, an adjustment can be made to the alternator charging rate. To make an adjustment to the voltage output, remove the cap (1) from the alternator regulator and change the regulator adjustment with a screwdriver.

Alternator Regulator
(1) Cap for adjustment screw.

To increase the voltage, turn the adjustment screw clockwise. The adjustment screw under the cap (1) has five position (number 1 is the last position clockwise).

Alternator Pulley Nut Tightening

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

Tighten nut that holds the pulley to a torque of 60 ± 7 N·m (44 ± 5 lb ft).

Starting System

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

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

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

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

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

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

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

Pinion Clearance Adjustment

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

Connection For Checking Pinion Clearance
(1) Connector (from Motor terminal on solenoid to motor). (2) SW terminal. (3) Ground terminal.

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

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

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

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

Pinion Clearance Adjustment
(4) Shaft nut. (5) Pinion. (6) Pinion clearance.

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

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

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

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