Basic Engine Troubleshooting

Introduction

Troubleshooting can be difficult. The Troubleshooting Index gives a list of possible problems. To make a repair to a problem, see the possible cause and corrective action on the pages that follow. Some corrective action procedures direct you to follow PEEC Engine Test Procedure P- or PEEC Engine Diagnostic Code, These procedures are in Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

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

Service personnel may remember similar complaints which were corrected by a previous method of troubleshooting. However, just because the complaint is the same the cause for the complaint can be different.

Be sure to get a good description of the problem from the operator and/or the person who owns the vehicle. What they tell you about the problem can save you time and make the repair job faster and easier.

Troubleshooting Problem List

1. Loud Combustion Noise

2. Fuel Consumption Too High

3. Too Much Black Or Gray Smoke

4. Too Much White Or Blue Smoke

5. Engine Has Low Oil Pressure

6. Engine Overheating

7. Engine Over Cooling

8. Coolant Leaks Outside of Engine

9. Coolant Leaks at the Overflow Tube

10. Coolant Leakage Inside Engine

11. Fuel in Crankcase Oil

NOTE: For PEEC System Troubleshooting, see Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

Troubleshooting Problems

Problem 1: Loud Combustion Noise

Probable Cause:

1. Bad quality or water in fuel

Follow the recommendations given in Special Instruction, Form No. SEHS7067, Fuel Recommendations For Caterpillar Diesel Engines. Also, Special Instruction, Form No. SEHS6947 has fuel correction factors and tables.

2. Defective fuel injection nozzle

Remove the fuel nozzles. Use the procedure given in the Testing and Adjusting section to test the fuel nozzles.

3. Defective fuel injection pump

An injection pump can have a good fuel flow coming from it but cause rough running because of slow timing that is caused by wear on the bottom end of the plunger. See the Testing and Adjusting section for the correct specifications and procedure to check the plungers and lifters.

4. Wrong fuel injection timing

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

5. Wrong timing position sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

6. PEEC system component fault

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

Problem 2: Fuel Consumption Too High

NOTE: Make reference to Section I, Understanding Truck Performance Complaints, in the Truck Performance Diagnostic Guide, Form No. SEBD0808 for additional information other than engine related problems.

Probable Cause:

1. MPG Measurement errors

Follow truck high fuel consumption check list:

* Miles measured correctly* Fuel measured correctly* Comparison to other trucks* Different truck or engine specifications* Different operating loads* Different operating modes

2. Bad quality or water in fuel

Follow the recommendations given in Special Instruction, Form No. SEHS7067, Fuel Recommendations For Caterpillar Diesel Engines. Also, Special Instruction, Form No. SEHS6947 has fuel correction factors and tables.

3. Fuel system leaks

Inspect the fuel system for leaks and make repairs or replacements as needed.

4. Excess idle time

Shut engine off when not in use.

5. Excess road speed or operation at high engine speeds

Reduce road speed and follow progressive shifting driving guidelines.

6. Excess wind drag

Decrease cab to trailer gap, add air deflector.

7. Brakes dragging

Adjust or repair brakes.

8. Fuel and combustion noise (knock)

Check items listed in Problem Nos. 3, 6, and 7. SEE TROUBLE SHOOTING GUIDE.

9. Wrong fuel injection timing

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

10. Wrong timing position sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

11. Wrong Rack Position Sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

Problem 3: Too Much Black Or Gray Smoke

Probable Cause:

1. Not enough air for combustion

Check for a plugged air cleaner element or blockage in the air lines. Follow the procedures in the Testing and Adjusting section to check inlet manifold pressure and aftercooler core leakage.

2. Defective fuel injection nozzle

Remove the fuel nozzles. Use the procedure given in the Testing and Adjusting section to test the fuel nozzles.

3. Wrong fuel injection timing

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

4. Wrong timing position sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

5. Wrong Rack Position Sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

6. PEEC system component fault

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

Problem 4: Too Much White Or Blue Smoke

Probable Cause:

1. Too much oil in engine

Do not put too much oil in the crankcase. If the oil level in the crankcase goes up as the engine is used, check for fuel in the crankcase. Make repairs or replacements to the fuel injection lines and nozzles as needed to keep fuel out of the crankcase.

2. Engine misfires or runs rough

Check items listed in Problem No. 3. Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

3. Wrong fuel injection timing

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

4. Wrong timing position sensor calibration

Refer to Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

5. Coolant in combustion system

Coolant in the combustion chamber can cause white smoke. A cracked cylinder head or liner, also a bad cylinder head gasket are possible causes for this condition.

6. Failed turbocharger oil seal

Check inlet manifold and aftercooler core for oil. Make a repair or replacement of the turbocharger as needed.

7. Worn valve guides

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

8. Worn piston rings

Worn piston rings and/or cylinder walls can be the cause of blue smoke and can cause a loss of compression. Make a visual inspection of the cylinder walls and piston rings. If necessary, measure the cylinder walls and piston rings. For the cylinder and piston ring specifications, see the Specifications module. NOTE: High wear at low mileage is normally caused by dirt coming into the engine with the inlet air.

Problem 5: Engine Has Low Oil Pressure

Probable Cause:

1. Low engine oil level

Check engine oil level and fill to proper level.

2. Oil leaks

Check for loose oil filter or oil supply lines, etc.

3. Dirty oil filter or cooler core

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 and fill the engine with clean oil to the correct level.

4. Diesel fuel in lubricating oil

Find the place where diesel fuel gets into the lubrication oil. Make repairs as needed. Remove any oil that has diesel fuel in it. Install new oil filters and fill the engine with clean oil to the correct level.

5. Too much clearance between rocker arm shaft and rocker arms

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

6. Oil pump suction pipe has a defect.

Replacement of the pipe is needed.

7. Relief valve for oil pump does not operate correctly

Clean valve and housing. Install new parts as necessary.

8. Oil pump has a defect

Make a repair or replacement of the oil pump as needed.

9. Too much clearance between camshaft and camshaft bearings

Install new camshaft and camshaft bearings if necessary.

10. Too much clearance between crankshaft and crankshaft bearings

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

11. Too much bearing clearance for idler gear

Inspect bearings and make replacements as necessary.

12. Piston cooling tubes not installed

Install piston cooling tubes.

13. Defective oil pressure gauge

Replace oil pressure gauge

14. PEEC system component fault

Follow PEEC Engine Diagnostic Code 46.

Problem 6: Engine Overheating

Probable Cause:

1. Low coolant level

If the coolant level is too low, not enough coolant will go through the engine and radiator. This lack of coolant will not take enough heat from the engine and there will not be enough flow of coolant through the radiator to release the heat into the cooling air. Low coolant level is caused by leaks or wrong filling of the radiator. With the engine cool, be sure the coolant can be seen at the low end of the fill neck on the radiator top tank.

2. Bad temperature gauge

A temperature gauge which does not work correctly will not show the correct temperature. If the temperature gauge shows that the coolant temperature is too hot but other conditions are normal, either install a gauge you know is good or check the cooling system with the 8T0470 Thermistor Thermometer Group.

3. Dirty Radiator

Check the radiator for debris between the fins of the radiator core which prevents free air flow through the radiator core. Check the radiator for debris, dirt, or deposits on the inside of the radiator core which prevents free flow of coolant through the radiator.

4. Loose belt(s)

Loose fan or water pump belts will cause a reduction in air or water flow. Tighten the belts according to the BELT TENSION CHART that is shown in the Specification Module.

5. Bad Hose(s)

Bad hoses with leaks can normally be seen. Hoses that have no visual leaks can "collapse" (pull together) during operation and cause a restriction in the flow of coolant. Hoses become soft and/or get cracks after a period of time. Hoses must be changed after 50,000 miles or a year of use. The inside can become loose, and the loose particles of the hose can cause a restriction in the flow of coolant.

6. Shunt Line Restriction

A restriction of the shunt line from the radiator top tank to the engine front cover, or a shunt line not installed correctly, will cause a reduction in water pump efficiency. The result will be low coolant flow and overheating.

7. Shutters not opening correctly

Check the opening temperature of the shutters. The shutters must be completely closed at a temperature below the fully open temperature of the water temperature regulators. Also, verify that fan control switches or viscous fans are operating correctly.

8. Bad water temperature regulator (thermostat)

A regulator that does not open, or only opens part of the way, can cause above normal heating. See the Testing and Adjusting section for the procedure to test water temperature regulators.

9. Bad Water Pump

A water pump with a loose impeller does not pump enough coolant for correct engine cooling. A loose impeller can be found by removing the water pump, and by pushing the shaft back and pulling it forward. If the impeller has no damage, check the impeller clearance. The clearance between the impeller and the housing is 0.56 to 1.50 mm (.022 to .059 in).

10. Air in cooling system

Air can get into the cooling system in different ways. The most common causes are not filling the cooling system correctly, and combustion gas leaking into the system. Combustion gas can get into the system through inside cracks or bad cylinder head gaskets. Air in the cooling system causes a reduction in coolant flow and bubbles in the coolant. Air bubbles hold coolant away from engine parts, preventing heat flow.

Air in the cooling system can be found by the BOTTLE TEST. The equipment needed to make this test is a one pint bottle, a bucket of water, and a hose which will fit the end of the overflow pipe of the radiator.

Before testing make sure the cooling system is filled correctly. Use a wire to hold the relief valve in the radiator cap open. Install the radiator cap and tighten it. Put the hose over the end of the overflow pipe.

Start the engine and operate it at high idle rpm for a minimum of five minutes after the engine is at normal operating temperature. Use a cover on the radiator core to keep the engine at operating temperature. After five or more minutes at operating temperature, place the loose end of the hose in the bottle filled with water. Put the bottle in the bucket of water with the top down. If the water gets out of the bottle in less than forty seconds, there is too much exhaust gas leakage into the cooling system. Find the cause of the air or gas getting into the cooling system and correct as necessary.

11. Wrong fan, fan or shroud not in correct position

A wrong fan, or a fan or shroud in a wrong position will cause a reduction or a loss of air flow through the radiator. The fan must be large enough to send air through most of the area of the radiator core. Make sure the fan size, fan shroud, and position of fan and shroud are according to the recommendations of the Truck Manufacturer.

12. Radiator too small

A radiator which is too small does not have enough area to release the heat to the cooling air. This will cause the engine to run at higher than normal temperatures. Make sure the radiator size is according to the recommendations of the Truck Manufacturer.

13. Not enough air flow through radiator because of restriction in engine compartment

The air flow through the radiator comes out of the engine compartment. Make sure the filters, air conditioners, and similar items are not installed in a way which prevents free flow of air into and out of the engine compartment.

14. High outside temperature

When outside temperatures are too high for the rating of the cooling system, there is not enough temperature difference between the outside air and coolant temperatures. To get better cooling, use the truck in a lower gear.

15. Operating at high altitude

The cooling capacity of the cooling system goes down as the truck is used at higher altitudes. A system, under pressure, large enough to keep the coolant from boiling must be used.

16. Engine used in a lug condition

"Lugging" (when the truck is used in a gear too high for engine rpm to go up as accelerator pedal is pushed farther down, or when the truck is used in a gear where engine rpm goes down with accelerator pedal at maximum travel) the engine causes the engine rpm and fan rpm to be low. This low rpm causes a reduction in air flow through the radiator, and a reduction in the flow of coolant through the system. This combination of less air and less coolant flow during high input of fuel will cause above normal heating.

17. Air inlet restriction

Restriction of the air coming into the engine causes high cylinder temperatures and more than normal amount of heat to pass to the cooling system. Check for a restriction with a water manometer or a vacuum gauge (which measures in inches of water). Connect the gauge to the engine air inlet between the air cleaner and the inlet to the turbocharger. With gauge installed, run engine at full load rpm and check the restriction. Maximum restriction of air inlet 635 mm (25 inches) of water. If the indication is higher than the maximum permissible restriction, remove the dirt from the filter element, or install a new filter element and check the restriction again. If the indication is still too high, there must be a restriction in the inlet piping.

18. Exhaust restriction

Restriction in the exhaust system causes high cylinder temperatures and more than normal amount of heat to pass to the cooling system. To see if there is an exhaust restriction, make a visual inspection of the exhaust system. Check for damage to piping or for a bad muffler. If no damage is found, check the system for back pressure from the exhaust (pressure difference measurement between exhaust outlet and atmosphere). The back pressure must not be more than 1016 mm (40 in) of water. You can also check the system by removing the exhaust pipes from the exhaust manifolds. With the exhaust pipes removed, start and run the engine to see if the problem is corrected.

19. Fuel injection timing not correct

Check and make necessary adjustments as given in the Testing and Adjusting section.

20. Transmission problems

Power-shift or automatic transmissions that are cooled by the engine cooling system can cause above normal heating if they are out of adjustment or not working correctly. See the transmission Service Manual for the correct adjustments.

Problem 7: Engine Over Cooling

Probable Cause:

1. Long idle periods

When the engine is running with no load, only a small quantity of fuel is burnt and engine heat is removed too fast.

2. Very light load

Very light loads, and a very slow speed or downhill travel can cause overcooling because of the low heat input of the engine. The installation of shutters helps to correct this condition.

3. Bad water temperature regulator (thermostat)

A regulator that is "stuck" open (will not move to the closed position) will cause overcooling. A thermostat that is stuck between the open and closed positions, or only opens part of the way, can cause overcooling when the truck has a light load. Also, coolant leaks around the thermostat, such as vent lines, can cause overcooling.

Problem 8: Coolant Leaks Outside Of Engine

Probable Cause:

1. Leaks in hoses or connections

Check all hoses and connections for visual signs of leakage. If no leaks are seen, look for damage to hoses or loose clamps.

2. Leaks in the radiator and/or expansion tank

Put pressure to the radiator and/or expansion tank with the 9S8140 Cooling System Pressurizing Pump Group and check for leaks. Refer to Testing Radiator And Cooling System For Leaks in Testing And Adjusting Section.

3. Leaks in the heater

Put pressure to the cooling system with the 9S8140 Cooling System Pressurizing Pump Group and check the heater for leaks. Refer to Testing Radiator And Cooling System For Leaks in Testing And Adjusting Section.

4. Leaks in the water pump

Check the water pump for leaks before starting the engine, then start the engine and look for leaks. If there are leaks at the water pump, repair or install a new water pump.

5. Cylinder head gasket leakage

Look for leaks along the surface of the cylinder head gasket. If you see leaks, install a new head gasket.

Problem 9: Coolant Leaks At The Overflow Tube

Probable Cause:

1. Bad pressure cap or relief valve

Check the sealing surfaces of the pressure cap and the radiator to be sure the cap is sealing correctly. Check the opening pressure and sealing ability of the pressure cap or relief valve with the 9S8140 Cooling System Pressurizing Pump Group. Refer to Checking Pressure Cap in Testing And Adjusting Section.

2. Engine runs too hot

If coolant temperature is too high, pressure will be high enough to move the cap off of the sealing surface in the radiator and cause coolant loss through the overflow tube. See Problem 6: Engine Overheating.

3. Expansion tank too small or installed wrong

The expansion tank can be either a part of the radiator or it can be installed separately from the radiator. The expansion tank must be large enough to hold the expansion of the coolant as it gets warm or has sudden changes in pressure. Make sure the expansion tank is installed correctly, and the size is according to the recommendations of the Truck Manufacturer.

4. Cylinder head gasket leakage or crack(s) in cylinder head or cylinder block

Remove the radiator cap and, with the engine running, look for air bubbles in the coolant. Bubbles in the coolant are a sign of probable leakage at the head gasket. Remove the cylinder head from the engine. Check cylinder head, cylinder walls and head gasket surface of the cylinder block for cracks. When the head is installed, use a new head gasket, spacer plate gasket, water seals, and O-ring seals.

Problem 10: Coolant Leakage Inside Engine

Probable Cause:

1. Cylinder head gasket leakage

If the cylinder head gasket leaks between a water passage and an opening into the crankcase, coolant will get into the crankcase.

2. Crack(s) in cylinder head

Crack(s) in the upper surface of the cylinder head, or an area between a water passage and an opening into the crankcase, can allow coolant to get into the crankcase.

3. Crack(s) in cylinder block

Crack(s) in the cylinder block between a water passage and the crankcase will let coolant get into the crankcase.

Problem 11: Fuel In Crankcase Oil

Probable Cause:

1. Loose inner fuel injection line nut(s)

A loose fuel injection line nut or a bad O-ring seal on the end of the adapter inside the cylinder head can cause fuel leakage into the crankcase. Check for a bad O-ring seal and tighten nuts to 40 ± 7 N·m (30 ± 5 lb ft).

2. Fuel nozzle leaks

Loose bleed screw or leaking bleed screw washer will cause fuel dilution in the crankcase. Check for bad bleed screw washers or damaged bleed screw washer face. Make sure the bleed screws are tightened to 2.2 ± 0.8 N·m (20 ± 7 lb in).

NOTE: Any time the bleed screws are loosened or removed the washer (seal) must be replaced to help prevent leakage.

BrakeSaver Troubleshooting

There are two operation checks that are fast and need no special equipment. One check is the "Pull-Down rpm Check" to see if the BrakeSaver can give full braking force. The other check is the "Klunk Check" to see if the valve spool in the BrakeSaver control valve has free movement. These two check give an approximate indication that the BrakeSaver has the correct operation.

Pull-Down RPM Check

NOTE: The engine must give rated horsepower for this test to have accuracy.

1. Actuate the brakes, put the transmission in NEUTRAL and operate the engine at high idle rpm (accelerator pedal all the way down).

2. Make a record of the engine rpm.

3. Put the BrakeSaver control to the full ON position.

4. Make a record of the engine rpm with the BrakeSaver full on.

5. The engine rpm with the BrakeSaver full on must be 150 ± 25 rpm less than the engine rpm with the BrakeSaver off.

NOTE: If the difference in rpm is less than 125 rpm, the BrakeSaver is not giving full braking force.

NOTE: If the difference in rpm is more than 175 rpm, check the air pressure to the BrakeSaver control valve. The air pressure must not be more than 345 kPa (50 psi).

Show/hide table

NOTICE
Do not run the engine at high idle rpm with the BrakeSaver ON for more than 15 seconds at a time. Let the engine run at low idle with the BrakeSaver off for five minutes to keep from getting the engine cooling system too hot.

Klunk Check (Check For Free Movement Of The Valve Spool)

1. Run the engine until the truck air system is at its maximum pressure and then stop the engine.

2. Put the BrakeSaver in the full ON position before the air pressure in the truck air system gets below 480 kPa (70 psi).

Gauge Holes For Troubleshooting
(1) Oil pressure from the BrakeSaver. (2) Oil pressure from the engine. (3) Oil pressure to the BrakeSaver. (4) Test point for BrakeSaver oil temperature. (5) Oil pressure to the engine. (6) Air pressure hole from the control valve. (7) Oil pressure to the cooler. (8) Oil pressure from the cooler.

3. Put the BrakeSaver in the OFF position. A noise ("KLUNK") must be heard at the BrakeSaver control valve as the valve spool hits the cover at the air inlet end of the control valve.

4. If the noise is not heard at the BrakeSaver control valve, remove and disassemble the control valve.

* A damaged valve body.* Damaged or worn springs in the valve spool.* Damaged or worn valve spool.* Damaged or worn O-ring seals or diaphragm in the control valve.* Closed holes (small holes to feel pressure) in the side of the valve spool.

For specific problems, make reference to the BrakeSaver Troubleshooting Problem List.

BrakeSaver Troubleshooting Problem List

1. BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The MANUAL Position.

2. BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The AUTOMATIC-MANUAL Position.

3. BrakeSaver Oil Temperature Is Too High.

4. BrakeSaver Does Not Turn OFF Or Become Empty.

5. Oil Leakage From The Flywheel Housing.

6. Oil Leakage From The Clutch Housing Or Transmission.

Engine Vibration Troubleshooting

The troubleshooting chart provides a definite sequence to be followed for a logical procedure to determine the frequency and amplitude of vibration so that the source of the vibration can be located and corrected.

1. The customer must be asked questions to determine whether his complaint is valid, or whether his diagnosis of the actual problem is correct.

Some of the questions that must be asked are as follows:

* What components are vibrating?* In what speed range does this vibration become excessive?* Does clutch operation affect the vibration?* What is the history of the problem?

2. Run the engine through the idle speed range and note all vibrating components. Look for any loose or broken mounts, brackets, and fasteners. Repair and tighten any fixtures.

3. Check idle speed range with clutch disengaged. If vibrations subside, there is a balance problem with the clutch disc. The clutch disc must be repaired or replaced.

4. Further analysis requires the use of a vibration instrument. Any instrument which can accurately measure the displacement of the vibration (usually in mils-inch/1000) and the frequency (cycles per second) will be sufficient.

NOTE: The 4C3030 Vibration Analyzer Group can be used to provide a quick and complete identification of all vibration frequencies present in a constant speed measurement. Make reference to Operation Manual, Form No. NEHS0525 for additional information for troubleshooting vibration complaints with the 4C3030 Vibration Analyzer Group.

NOTE: The following steps assume the use of a vibration instrument such as the IRD Mechanalysis Model 320. An equivalent instrument can also be used to analyze vibration. Make reference to Special Instruction, Troubleshooting Engine Vibration In Vehicular Equipment, Form No. SEHS7914 for additional information for troubleshooting vibration complaints.

5. Measure vibration of cab components which have the objectionable vibration.

Run engine slowly through the speed range and measure vibration with the instrument filter OUT. When peak amplitudes are found, run the engine at the speeds they occur and with the instrument filter IN, find the frequency of the vibration.

If the frequency of vibration is 1/2 times of engine rpm (1/2 order), the vibration is caused by a cylinder misfiring. This must be corrected before further vibration analysis is made.

If the frequency of vibration is 3 times engine rpm (3rd order), no corrective action can be taken on the engine because this is the firing frequency of the 3406B (PEEC) Engine. The problem is in the cab or chassis resonance.

If frequency is some order other than 1/2 or 3rd order vibrations, then further measurements must be made on the engine.

6. Measurements taken on the engine must be made perpendicular to the crankshaft at the front and rear of the engine in vertical and horizontal directions.

7. Record all vibrations over 4.0 mils and the engine rpm at which it occurs (100 rpm intervals are sufficient) with instrument filter OUT. Note any sudden increase and decrease in amplitudes. These occur in resonant speed ranges.

If no amplitudes exceed 4.0 mils, the engine is within Caterpillar Specs.

If amplitudes exceed 4.0 mils, the vibrations must be measured with the instrument filter IN to obtain the frequency of the vibrations.

8. Run the engine at high idle. With the instrument filter IN, check the frequency range and record any amplitudes over 4.0 mils and the corresponding frequency. Analysis of vibrations for the possible causes is done by identifying the frequency of the vibration and where on the engine it is the greatest magnitude.

NOTE: Make reference to Special Instruction, Troubleshooting Engine Vibration In Vehicular Equipment, Form No. SEHS7914 for additional information for troubleshooting vibration complaints.

Fuel System

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

* Not enough air for good combustion.* An overload at high altitude.* Oil leakage into combustion chamber.* Not enough compression.* Fuel injection timing retarded.

Fuel System Inspection

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

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

2. Check the fuel lines for fuel leakage. Be sure the fuel supply line does not have a restriction or a bad bend.

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

4. Remove any air that may be in the fuel system. Use the fuel priming pump to move fuel through low pressure part of the system. Fuel with air will return to the tank through the fuel return line.

To remove air from the fuel injection lines, loosen the fuel line nuts at the through the head adapter nozzles 1/2 turn. Crank engine with the starter motor until fuel without air comes from the fuel line connections. Tighten the fuel line nuts.

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

Fuel Transfer Pump

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

To check the fuel transfer pump pressure, disconnect the fuel line (from the filter) at the fuel injection pump housing inlet (1). Install a tee at inlet (1) and connect the fuel line to the tee. Connect a pressure gauge to the tee and start the engine.

Fuel Lines
(1) Fuel inlet.

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

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

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

Checking Engine Cylinders Separately

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

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

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

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

1. Steel wire brushing of nozzle tip.

2. Orifice wear.

Show/hide table

NOTICE
Do not test nozzles unless you have the correct service tools.

Testing Fuel Injection Nozzles

NOTE: FT1743 is a standard fuel line used between the through the head adapter and the nozzle. Bend the line to position nozzle in a vertical position in the extension and collector.

NOTE: For more information on the 5P4150 Nozzle Testing Group see, Special Instruction, Form No. SEHS7292.

5P4150 Nozzle Testing Group
(1) Nozzle assembly. (A) FT1743 Line Assembly. (B) 5P4244 Adapter. (C) 5P4721 Tube Assembly. (D) 8T0859 Gauge 0 to 25 000 kPa (0 to 3600 psi). (E) 8T0856 Gauge 0 to 6000 kPa (0 to 870 psi). (F) Gauge protector valve for 8T0859 Gauge. (G) FT1384 Extension and 8S2270 Fuel Collector. (H) Gauge protector valve for 8T0856 Gauge. (J) Gauge protector valve.

5P4150 Nozzle Testing Group
(K) Pump isolator valve. (L) On-Off valve.

Show/hide table

NOTICE
Be sure to use clean SAE J967 Calibration Fluid when tests are made. Dirty test fluid will damage components of fuel injection nozzles. The temperature of the test fluid must be 18 to 24°C (65 to 75°F) for good test results.

Nozzle Preparation For Test

Refer to Special Instruction, Form No. SEHS8627 for instructions for cleaning the nozzles.

Removing Carbon Dam
(1) Fuel injection nozzle. (2) Carbon dam. (3) Seal.

Remove seal (3) and carbon dam (2) from the nozzle. Before fuel injection nozzle (1) can be tested, all loose carbon around the tip of the nozzle must be removed with the 8S2258 Brass Wire Brush (M).

Show/hide table

NOTICE
Do not use a steel brush or a wire wheel to clean the nozzle body or the nozzle tip. Use of these tools can cause a small reduction of orifice size, and this will cause a large reduction in engine horsepower. Too much use of the 8S2258 Brass Wire Brush will also remove the coating that is on the nozzle for protection.

8S2245 Cleaning Kit
(M) 8S2258 Brass Wire Brush. (N) 6V4979 Carbon Seal Tool. (P) 8S2250 Nozzle Holding Tool.

Clean the groove for carbon seal dam (2) and the body of the nozzle below the groove with the 8S2258 Brass Wire brush (M). Remove the carbon, but be sure not to use the brush enough to cause damage to the body of the nozzle.

NOTE: A change in color in the area below the groove is normal and does not effect the body of the nozzle.

Fuel Injection Nozzle
(4) Bleed screw and seal.

Remove bleed screw and seal (4) from the nozzle.

NOTE: Any time the bleed screw is loosened or removed a new washer (seal) must be installed to help prevent leakage. The bleed screw and seal must be removed for all tests except, Bleed Screw Leakage Test.

Test Sequence

NOTE: It is necessary to have an accurate record of the test results for each nozzle that is tested. Make a record of the result for each nozzle test procedure on Form No. SEHS8144, Nozzle Test Record. These test sheets are available in a pad of 50 sheets, order one Form SEHS8144.

For fuel nozzle testing refer to Special Instruction, Form No. SEHS9083, Test Sequence For Caterpillar 7000 Series Fuel Nozzles.

The fuel injection nozzle can not be disassembled for cleaning or adjustment. Do the tests that follow to determine if the nozzle performance is acceptable.

Valve Opening Pressure (VOP) Test.Flush The Nozzle.Tip Leakage Test.Orifice Restriction Test.Bleed Screw Leakage Test

Show/hide table

When fuel injection nozzles are tested, be sure to wear eye protection. Test fluid comes from the orifices in the nozzle tip with high pressure. The test fluid can pierce (go through) the skin and cause serious injury to the operator. Keep the tip of the nozzle pointed away from the operator and into the 8S2270 Collector and FT1384 Extension.

Valve Opening Pressure Test (VOP)

1. Install 5P4721 Tube Assembly (C), 5P4244 Adapter and FT1743 Line Assembly on the tester.

2. Install the fuel injection nozzle on tube (A). Be sure the nozzle is inside FT1384 Extension (G) and 8S2270 Fuel Collector.

Nozzle Ready For Test
(F) Gauge protector valve. (K) Pump isolator valve. (L) On-Off valve.

Show/hide table

NOTICE
Put a shop towel around the upper part of the nozzle to take in any fuel leakage.

3. Close on-off valve (L). Open pump isolator valve (K).

4. Open gauge protector valve (F). Operate the pump to make a slow increase in pressure until the valve in the fuel injection nozzle just starts to open. Read the maximum gauge pressure at the instant fluid flows from the tip.

NOTE: It is possible for the pressure reading of the gauge to go down fast if the valve makes a noise (chatters) when it opens. It is also possible for the pressure reading of the gauge to be almost constant when the valve in the fuel injection nozzle opens.

NOTE: The valve in the fuel injection nozzle can be good and still not make noise (chatter), or not have a very fine vapor (spray) from the orifices in the tip of the fuel injection nozzle during Step 4.

If the opening pressure is not withing specifications, do not use the fuel injection nozzle again.

Valve Opening Pressure (VOP) Specifications

Flush The Nozzle

1. Close gauge protector valve (F). Close on-off valve (L). Open pump isolator valve (K).

NOTE: Make sure nozzle extends inside and below the top of FT1384 Extension (G).

2. Operate the pump rapidly for three full strokes.

Tip Leakage Test

1. Remove all fuel from the nozzle tip and body with a clean cloth.

2. Put a clean cloth around the body of the nozzle to take in any leakage from the bleed screw hole and prevent any fuel leakage to drain down to the tip of the nozzle.

Nozzle Ready For Test
(F) Gauge protector valve. (K) Pump isolator valve. (L) On-Off valve.

3. Open gauge protector valve (F). Close on-off valve (L). Open pump isolator valve (K).

4. Make and hold for 15 seconds a pressure of 1380 kPa (200 psi) less than the opening pressure measured in Valve Opening Pressure Test (VOP) and make a note of the number of drops that fall.

Tip Leakage Specification

5. If the nozzle is not within specifications, DO NOT USE THE NOZZLE.

Orifice Restriction Test

1. Close gauge protector valve (F) and on-off valve (L). Open pump isolator valve (K).

2. Point the tip of the fuel injection nozzle into the 8S2270 Fuel Collector and FT1384 Extension (G).

3. Make a rapid increase in pressure and look at the orifice discharge (shape of discharge).

The discharge must be the same through all six orifices. Any change either vertically or horizontally, is an indication of a bad nozzle.

Good Nozzle (Use Again)

Typical Discharge For Orifice With A Restriction (Replacement Necessary)

Typical Discharge With Horizontal Distortion (Replacement Necessary)

Typical Discharge With Vertical Distortion (Replacement Necessary)

Bleed Screw Leakage Test

1. Install bleed screw and a new seal (4) in fuel injection nozzle. Tighten the bleed screw to a torque of 2.2 ± 0.8 N·m (20 ± 7 lb in) with 6V4980 Torque Driver.

Show/hide table

NOTICE
Do not tighten the bleed screw more than the torque shown. The bleed screw or seal can be damaged.

2. Put the tip of the fuel injection nozzle down inside the 8S2270 Fuel Collector and FT1384 Extension (G).

3. Close on-off valve (L). Open gauge protector valve (F) and pump isolator valve (K).

4. Pump the tester until fuel injection nozzle is full of fluid and the pressure on the gauge is 20 700 kPa (3000 psi).

NOTE: 15 or 20 strokes of the pump can be necessary for the pressure to get to 20 700 kPa (3000 psi).

Bleed Screw Leakage Specification

5. If there is leakage, replace the sealing washer. Inspect the washer face of the bleed screw for damage, install a new screw if necessary. Test the nozzle again. If there is still leakage, the fuel injection nozzle must be replaced.

Installing Carbon Dam
(2) Carbon dam. (3) Seal. (N) 6V4979 Carbon Seal Tool.

6. If no fuel leakage is found, the fuel injection nozzle is acceptable. Put a new washer (3) on the nozzle. Install a new carbon dam (2) in nozzle groove with 6V4979 Carbon Seal Tool (N).

NOTE: Make sure the correct washer (3) is used when the nozzle assembly is installed.

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.

Show/hide table

Fuel injection lines which are bent, damaged or rubbing can leak and cause a fire. Replace any lines which have damage or leaks that can not be corrected when tightened to the correct torque.

The nuts that hold a fuel injection line to an injection nozzle and 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).

Show/hide table

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

Fuel Injection Lines
(1) A vertical line through the number one injection pump

Checking The Plunger And Lifter Of An Injection Pump

NOTE: There are no different size spacers available to adjust the timing dimension of the fuel injection pumps. If the pump plunger or the lifter is worn, they must be replaced. Because there is no adjustment to the timing dimension possible, there is NO OFF ENGINE LIFTER SETTING PROCEDURE.

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

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

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

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

Removal And Installation Of Fuel Injection Pumps

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

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

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

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

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

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

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

4. Install and tighten nut (D).

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

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

Removal Of Fuel Injection Pumps

Show/hide table

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

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

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

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

Fuel Rack Against Timing Pin In The Zero Position
(3) 6V4186 Timing Pin.

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

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

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

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

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

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

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

Show/hide table

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

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

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

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

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

Fuel Injection Pump Housing
(9) 8S2244 Extractor.

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

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

Installation Of Fuel Injection Pump

Show/hide table

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

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

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

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

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

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

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

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

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

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

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

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

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

Show/hide table

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

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

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

Show/hide table

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

11. Install the fuel injection lines to the pump and tighten to 40 ± 7 N·m (30 ± 5 lb ft). See Fuel Injection lines in this section for more information.

Show/hide table

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

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

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

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

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

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

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

Illustration 1. Correct installation in full load position.

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

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

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

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

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

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

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

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

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

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

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

Show/hide table

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

Turbocharger Air Inlet Opening

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

b. Set the governor control at low idle. No pressure applied to the accelerator pedal (pedal up).

Stopping The Engine

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 opening. To avoid crushed fingers, do not put fingers between plate and air inlet opening.

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

Finding Top Center Compression Position For No. 1 Piston

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

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

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

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

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

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

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

NOTE: If the flywheel is turned beyond the point that the timing bolt engages in the threaded hole, the flywheel must be turned opposite normal engine rotation approximately 45 degrees. Then turn the flywheel in the direction of normal rotation until the timing bolt engages with the threaded hole. The reason for this procedure is to make sure the play is removed from the gears when the No. 1 piston is put on top center.

3. Remove the front valve cover from the engine.

Checking No. 1 Intake And Exhaust Valves

4. The intake and exhaust valves for the No. 1 cylinder are fully closed if No. 1 piston is on the "compression stroke" and the rocker arms can be moved by hand. If the rocker arms can not be moved and the valves are slightly open the No. 1 piston is on the "exhaust stroke".

NOTE: When the actual stroke position is identified, and the other stroke position is needed, it is necessary to remove the timing bolt from the flywheel, turn the flywheel counterclockwise 360°, and reinstall the timing bolt.

Checking Engine Timing And Timing Advance With 8T5300 Engine Timing Indicator Group

1. Turn the engine off at the ignition switch.

Connect ECAP To The Data Link

2. Disconnect the PEEC Data Link Connector (short pigtail out of the top of the PEEC ECM P1/J1 connector) from the truck wiring harness and connect the 8T5275 Harness and 8T8697 ECAP.

Transducer In Position
(1) Injection transducer. (2) Fuel injection line for No. 6 cylinder.

3. Make reference to Special Instruction, Form No. SEHS8580 for the correct installation and operation of the 8T5300 Engine Timing Indicator Group. Install the injection transducer adapter and injection transducer in either fuel line number 1 or number 6 at the fuel injection pump. Install the TDC indicator in the flywheel housing and connect the cables to the Engine Timing Indicator and perform a calibration check as given in the Special Instruction.

Transducer In Position
(3) TDC magnetic transducer.

4. Start the engine and run at low idle until the engine has warmed up enough to switch from the cold mode operation to the warm mode operation. Cruise control ON/OFF switch in the OFF position.

5. Select the Status Mode from the main menu on the ECAP service tool that displays timing advance, desired timing advance, static timing specification, and estimated dynamic timing. See Special Instruction, Form No. SEHS8741 for more information on the procedure to select the status screen.

6. Use the Cruise Control Switches and run the engine at several different speeds in the PTO mode control. Make a record of the following measurements after they have stabilized on the tooling:

a. The Estimated Dynamic Timing displayed on the ECAP and the timing angle displayed on the Engine Timing Indicator.

b. On the ECAP, the difference between desired timing advance and actual timing advance.

NOTE: Use the measurements from Step 6 with Steps 7, 8 and 9 to determine if an adjustment or repair is needed.

7. The Estimated Dynamic Timing reading displayed on the ECAP should be equal to the timing angle reading displayed on the Engine Timing Indicator within ± 2.50 degrees. This indicates the timing advance actuator and timing position sensor are working correctly and the static injection timing is correctly set.

8. The Estimated Dynamic Timing reading on the ECAP and the timing angle displayed on the Engine Timing Indicator are not within ± 2.50 degrees. The difference is about constant for all engine speeds. This indicates the timing advance actuator and timing position sensor are working correctly - the static fuel injection timing is not correct. Follow the procedure given in Checking Engine Timing By Timing Pin Method to set the static fuel injection timing. Repeat Steps 5 and 6 after checking and adjusting the static timing.

9. On the ECAP service tool the timing advance reading varies by more than ± 0.30 degrees from the desired timing advance angle shown. This indicates that the timing actuator and sensor are not working correctly. To troubleshoot the timing advance actuator see Troubleshooting 3406B (PEEC) Truck Engine Test Procedures, Form No. SENR3479.

Checking Engine Timing By Timing Pin Method

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

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

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

Timing Pin Installed
(2) 6V4186 Timing Pin.

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

Timing Position Sensor Cover
(3) Cover. (4) Housing. (5) Timing Solenoid (BTM).

4. Remove the timing position sensor cover (3) from housing (4).

5. Rotate the crankshaft clockwise 15° as seen from the flywheel end of the engine. Observe the motion of the timing advance power piston through housing (4).

6. Rotate the crankshaft counterclockwise as viewed from the rear of the engine until the timing advance power piston moves to its fully retracted position and light pressure is applied to timing pin (2).

Show/hide table

NOTICE
Do not apply excessive force to rotate the engine with the timing pin installed. Excessive force will shear off the timing pin and/or cause fuel pump damage. Apply only enough force to retract the timing actuator power piston.

Install Timing Bolt
(6) 9S9082 Engine Turning Tool. (7) Timing bolt.

7. Put the timing bolt in the timing hole in the flywheel housing. If the bolt can be installed in the timing hole in the flywheel, the static injection timing of the fuel injection pump is correct.

8. If the timing bolt does not go into the timing hole in the flywheel, the timing is not correct. Perform the following steps to adjust the fuel injection pump static timing.

a. Remove timing advance solenoid (5).

b. Remove timing advance housing (4).

Automatic Timing Advance Unit (Governor and Fuel Pump Drive Group)
(8) Bolts.

c. Loosen the four bolts (8) on the timing advance. With the timing pin installed in the fuel pump and the timing bolt removed, turn the engine crankshaft clockwise as viewed from the rear of the engine a minimum of 30 degrees. Make sure that the power piston of the timing advance does not move from its fully retracted position.

d. Lightly tighten two of the four timing advance bolts to 2.3 N·m (21 lb in). (FINGER TIGHT ONLY so as not to bend the timing pin).

e. Rotate the crankshaft counterclockwise as viewed from the rear of the engine (direction of engine rotation) slowly until the timing bolt can be installed in the flywheel. The number one piston is now at top dead center.

f. Tighten the four timing advance bolts (8) to a torque of 10 N·m (7 lb ft). Remove the timing pin from the fuel injection pump.

g. Tighten the four timing advance bolts to a torque of 55 ± 7 N·m (41 ± 5 lb ft). Remove the timing bolt from the flywheel.

h. Turn the crankshaft two complete revolutions counterclockwise as viewed from the rear of the engine to make sure that the timing advance piston is in the fully retracted position. Repeat Steps 6 and 7 to check the timing again to see if the timing pin will go into the groove in the fuel pump camshaft and the timing bolt will go into the flywheel.

i. If the timing is not correct repeat the Steps c through h again.

j. If the timing is correct, remove the timing bolt from the flywheel and remove the timing pin from the fuel pump.

Location Of Screwdriver While Holding Bellcrank

k. Rotate the timing position sensor bellcrank clockwise by inserting a No. 2 Phillips screwdriver between the arm of the bellcrank in contact with the timing position sensor until the screwdriver can be inserted into the hole in the cover to hold the bellcrank in position.

Hold Timing Position Sensor Bellcrank In Position

l. Install the gasket and timing advance housing (4).

m. Remove the screwdriver to allow the bellcrank to contact the power piston.

9. Check the timing position sensor calibration using the procedure given in Timing Position Sensor Calibration.

10. Install the timing solenoid. Make sure the arm of the timing solenoid is in the center groove of the control spool collar.

11. Install the timing advance position sensor cover (3).

Timing Position Sensor Calibration

Refer to Special Instruction, Form No. SEHS8746, Using The 1U5540 Tool Group.

Remove Cover And Timing Advance Solenoid
(1) Solenoid wires. (2) Cover. (3) Timing Solenoid (BTM).

1. Shut the engine off. Turn key OFF.

2. Remove timing position sensor cover (2) and disconnect the 3 pin timing solenoid connector (P6/J6) that connects solenoid wires (1) to the engine wiring harness.

3. Remove timing solenoid (3) from the timing advance housing.

Install Timing Pin In Fuel Injection Pump
(4) 6V4186 Timing Pin.

4. Install 6V4186 Timing Pin (4) in the fuel injection pump housing as shown. Slowly rotate the crankshaft counterclockwise (as seen from the flywheel end of the engine) until timing pin (4) goes into the slot in the fuel pump camshaft.

NOTE: The following methods can be used to turn the engine crankshaft for installation of the timing pin:

* By using the 9S9082 Engine Turning Tool.* By turning the flywheel ring gear if the housing has access.* By turning on the crankshaft vibration damper bolts.

With the timing pin installed in the fuel injection pump camshaft slot, slowly rotate the crankshaft counterclockwise (CCW) until "STOP" is felt.

Show/hide table

NOTICE
Rotation of the crankshaft after "STOP" is felt will cause the timing pin to shear off in the fuel injection pump camshaft slot.

This procedure makes sure that the timing advance power piston is in the fully retracted position (moved toward rear of engine). Movement can be checked through the top of the timing advance housing by watching the collar that is engaged by the timing solenoid.

Install Timing Gauge Assembly
(5) 1U5425 Timing Gauge Assembly. (6) Bellcrank.

5. Install the 1U5425 Timing Gauge Assembly (5) through the timing solenoid hole on the in-board side of the timing advance housing.

The gauge assembly (block) must be positioned between the bearing on the power piston and the timing position sensor bellcrank (6). The gauge assembly (block) is inserted and rotated around the timing spool valve. Make sure that the tool is correctly seated on the bearing race and that the bellcrank is on the flat surface of the gauge block.

6. Disconnect the PEEC Data Link Connector (short pigtail out of the top of the ECM P1/J1 connector) from the truck harness. Connect the 8T5275 Harness and either the ECAP or DDT to the PEEC Data Link Connector.

7. Turn key ON, Engine OFF.

Show/hide table

NOTICE
Do not engage the starter or damage to the engine will be the result.

With the ECAP or DDT, select the status display that has "Timing Advance Position" from the main menu (see Special Instructions for the Service Tool used, for more information).

8. Read the "Timing Advance Position" on the ECAP or DDT display.

a. If the "Timing Advance" reading is 13.7 ± .4 degrees the timing position sensor is correctly calibrated.

b. If the "Timing Advance" reading is not 13.7 ± .4 degrees the timing position sensor needs adjustment as follows:

9. Keep electrical power on the ECM. On the ECAP or DDT, select the status display that has "Timing Position Sensor Calibration" from the main menu (see Special Instructions for the Service Tool used, for more information, Form No. SEHS8742 or SEHS8743).

Adjustment Of Timing Position Sensor
(7) Timing position sensor. (8) Locknut.

10. Use the 1U5536 Crowfoot Wrench to loosen locknut (8).

11. Turn timing position sensor (7) in or out until the ECAP or DDT indicates the timing position sensor is calibrated.

12. Tighten the locknut (8) to 55 ± 7 N·m (41 ± 5 lb ft).

13. Check the timing position calibration reading on the ECAP or DDT to make sure that the timing position sensor is still in calibration after tightening the locknut.

14. Turn key OFF.

15. Disconnect the ECAP or DDT from the ECM. Connect the PEEC Data Link Connector to the truck harness.

16. Remove the 1U5425 Timing Gauge Assembly.

17. Remove the 6V4186 Timing Pin. (Rotate the crankshaft in the clockwise direction as seen from the rear of the engine to release the pressure on the timing pin)

18. Install the Timing Solenoid (BTM) and make sure that the arm on the Timing Solenoid (BTM) is assembled in the groove of the timing advance servo collar.

19. Connect Timing Solenoid (BTM) connector to wiring harness (P6/J6). Install timing position sensor cover.

Rack Position Sensor Calibration

Refer to Special Instruction, Form No. SEHS8746, Using The 1U5540 Tool Group.

1. Shut the engine off. Turn key OFF.

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

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

Fuel Rack Against Timing Pin
(3) 6V4186 Timing Pin.

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

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

Show/hide table

NOTICE
Do not start the engine with bracket assembly (4) and compressor assembly (5) installed on the fuel injection pump housing. Engine overspeed can result.

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

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

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

7. Disconnect the PEEC Data Link Connector (short pigtail out of the top of the ECM P1/J1 connector) from the truck wiring harness and connect the 8T5275 Harness and either the ECAP or DDT.

8. Turn the ignition switch to the ON position without the engine running. Select the status display from the main menu that shows "Actual Rack Position" (see the Service Tool Special Instruction).

9. With the rack held back against the "zero pin", read the "Actual Rack Position" on the ECAP or DDT display.

a. If the "Actual Rack Position" reading is 9.50 ± 0.20 mm the Rack Position Sensor is correctly calibrated.

b. If the "Actual Rack Position" reading is not 9.50 ± 0.20 mm the Rack Position Sensor needs adjustment as follows:

Fuel Injection Pump And Rack Actuator Housing
(6) Clip assembly. (7) Cover.

10. Remove the wiring connectors from clip assembly (6). Do not disconnect any wiring at this time.

11. Remove the five bolts and cover (7) from the rack actuator housing.

Rack position Sensor Adjustment
(8) Wiring for Transducer Module. (9) Wiring for Rack Position Sensor. (10) Rack Position Sensor.

12. Use the 1U5536 Crowfoot Wrench and a 3/8 inch drive ratchet to loosen the locknut on Rack Position Sensor (10).

13. Make sure Rack Position Sensor wiring (9) is connected to Transducer Module wiring (8).

14. With electrical power to the ECM, select the status display that has "Rack Position Sensor Calibration" from the main menu on the ECAP or DDT (see Special Instructions for the Service Tool used, for more information, refer to Special Instruction Form No. SEHS8742 or SEHS8743).

15. With the rack held back against the timing pin, turn the collar on the Rack Position Sensor in or out until the ECAP or DDT indicates the Rack Position Sensor is calibrated.

16. Tighten the locknut to 55 ± 7 N·m (41 ± 5 lb ft).

17. Check the rack position calibration reading on the ECAP or DDT to make sure that the Rack Position Sensor is still in calibration after tightening the locknut.

18. Turn key OFF.

19. Install cover (7) and clip assembly (6) on rack actuator housing. Make sure not to pinch a wire between the cover and housing.

20. Install wiring connectors in clip assembly (6).

21. Remove the 6V4186 Timing Pin and install the plug in the top of the fuel injection pump housing.

22. Remove the 8T9198 Bracket Assembly and 1U5426 Compressor Assembly. Install the gasket and cover on the side of the fuel injection pump housing.

23. Disconnect the ECAP or DDT from the ECM. Connect the PEEC Data Link Connector to the truck harness.

Engine Speed Sensor Adjustment

Refer to Special Instruction, Form No. SEHS8746, Using The 1U5540 Tool Group.

Fuel Injection Pump And Rack Actuator Housing
(1) Clip assembly. (2) Cover.

1. Remove the wiring connections from clip assembly (1)

2. Remove the five bolts and cover (2) from the rack actuator housing.

Remove Rack Actuator Housing
(3) Housing. (4) Rack position sensor. (5) Wiring for Transducer Module. (6) Wiring for Engine Speed Sensor.

3. Disconnect the Engine Speed Sensor wiring (6) and the wiring for Rack Position Sensor (4) from Transducer Module wiring (5).

Remove Shutoff Lever Group
(3) Housing. (7) Shutoff lever and clip assembly. (8) Rack Solenoid (BTM).

4. Remove shutoff lever and clip assembly (7) from the center of housing (3).

5. Remove Rack Solenoid (BTM) (8) from housing (3).

6. Remove the bolts and remove housing (3) from the rack actuator center housing.

Engine Speed Sensor Adjustment
(9) Engine speed sensor.

7. Use the 5P0326 Crowfoot Wrench and a 3/8 inch drive ratchet to loosen the locknut on Engine Speed Sensor (9).

8. Turn Engine Speed Sensor (9) into the threads in the housing until it makes contact with the gear tooth on the fuel pump camshaft retainer. Back the Engine Speed Sensor out 1/2 turn ± 30 degrees. This gives a clearance of 0.76 ± 0.15 mm (.030 ± .006 in) between the camshaft retainer and the magnet on the end of Engine Speed Sensor (9).

9. Use the 5P0326 Crowfoot Wrench and tighten the locknut on Engine Speed Sensor (9) to a torque of 13 ± 2 N·m (10 ± 1 lb ft). Be careful to prevent rotation of the Engine Speed Sensor while tightening the locknut.

NOTE: Do not over torque locknut. Damage to Engine Speed Sensor may result.

Install Rack Actuator Housing
(3) Housing. (4) Rack Position Sensor.

10. To prevent damage to the Rack Position Sensor, install the gasket and housing (3) as follows:

a. Push the plunger (3/4 of its travel) into the Rack Position Sensor (4).

b. Push the fuel rack and magnetic connection toward the front of the engine.

c. Put the gasket and housing (3) in position and install the bolts.

d. Slowly pull the fuel rack and Rack Position Sensor plunger together until the magnet holds the two parts together.

Install Shutoff Lever Assembly
(10) Lever. (11) Pin. (12) Lever.

11. Install shutoff lever and clip assembly as follows:

a. Put the shutoff lever and clip assembly in position. Make sure the wiring from the Transducer Module is positioned over the top of the shutoff lever and clip assembly.

b. Push the shutoff solenoid plunger into the solenoid and hold in this position.

c. Make sure pin (11) is engaged correctly with manual shutoff lever (12) as shown.

d. Make sure lever (10) is in the correct position behind the end of the rack servo valve as shown.

e. Install the bolts to hold the shutoff lever and clip assembly in housing (3).

f. Check for correct operation of the manual shutoff lever.

12. Connect the wiring for Rack Position Sensor (4) and the wiring for the Engine Speed Sensor to the Transducer Module wiring.

13. Check and adjust the Rack Position Sensor if needed. Follow Rack Position Sensor Calibration procedure.

14. Install the Rack Solenoid (BTM) in housing (3). Make sure the lever on the rack solenoid engages correctly in the sleeve on the rack servo valve at assembly.

15. Install the gasket, cover, and connector clip on the end of housing (3).

16. Fasten the wiring connections in position on the clip assembly (1).

Throttle Position Sensor Adjustment

NOTE: If the vehicle is equipped with the Pedal-Mounted Throttle Sensor, no adjustment is required. If the vehicle is equipped with the Throttle Position Sensor the following adjustments should be made.

Throttle Position Sensor
(1) Rotary disc. (2) Pin.

1. Inspect the throttle linkage for loose, bent, broken, missing, or worn components. The throttle linkage should work smoothly without excessive drag and return to the low idle position without assistance in less than 1 second. Replace parts if needed.

2. Disconnect the PEEC Data Link Connector (short pigtail out of the top of the ECM P1/J1 connector) from the truck harness and connect either the ECAP or DDT to the PEEC Data Link Connector.

3. Turn the ignition switch to the ON position to provide power to the ECM.

4. Select the Status Mode from the main menu that has THROTTLE POSITION for one of the displays (see Service Tool Special Instructions). The ECAP or DDT will display throttle readings from 3 to 100 percent (no throttle to full throttle).

5. Observe the Duty Cycle of the throttle signal with the throttle at the low idle position using the ECAP or DDT (see Special Instruction, Form No. SEHS8807). The Duty Cycle readings range from 15 to 20% at low idle position. A slight movement of the pedal off the low idle stop should increase the Duty Cycle readings.

6. Actuate the throttle and return to the low idle position.

Correct Low Idle Position Adjustment

7. Adjust either the linkage low idle stop, if the system has one, or the throttle linkage until pin (2) is centered between the mechanical stop and the low idle edge indicator as shown.

Correct High Idle Position Adjustment

8. Advance the throttle to the high idle position. Adjust the throttle linkage until pin (2) is centered between the mechanical stop and the high idle edge indicator as shown.

9. A Duty Cycle reading of 80 to 85% should be displayed on the ECAP or DDT with the throttle at the high idle position. A slight movement of the pedal off the high idle stop should decrease the Duty Cycle readings.

10. Repeat Steps 5 through 9 as needed until the low and high idle adjustments are correct.

Show/hide table

NOTICE
Continued operation with pin (2) in contact with one of the mechanical stops can result in failure of the sensor.

11. Turn key OFF.

12. Disconnect the ECAP or DDT from the ECM. Connect the PEEC Data Link Connector to the truck harness.

Pedal-Mounted Throttle Sensor (If Equipped)

Pedal-Mounted Throttle Sensor

If the vehicle is equipped with the Pedal-Mounted Throttle Sensor, no adjustment is required.

The Pedal-Mounted Throttle Sensor can be installed in place of the Throttle Position Sensor on earlier engines as long as the engine has the correct Personality Module.

The Pedal-Mounted Throttle Sensor is mounted on the back of the OEM-supplied pedal. No adjustments are required for the Pedal-Mounted Throttle Sensor. Calibration of the Pedal-Mounted Throttle Sensor is done automatically by the ECM. The correct calibration can be displayed with the ECAP or the DDT. The correct percent throttle (governor control movement) is displayed as 3% with the throttle completely released, and 100% with the throttle completely depressed.

Engine Speed Measurement

6V3121 Multitach Group

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

Special Instruction, Form No. SEHS7807 is with the 6V3121 Multitach Group and gives instructions for the test procedure.

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

Special Instruction, Form No. SEHS8029 is with the group and gives instructions for use of the 6V4950 Injection Line Speed Pickup Group.

NOTE: An ECAP or DDT can also be used to check engine rpm.

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

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

Air flow through the air cleaner must not have a restriction (negative pressure difference measurement between atmospheric air and air that has gone through air cleaner) of more than 635 mm (25 in) of water.

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 1016 mm (40 in) 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 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 Fuel Setting And Related Information Fiche. Development of this information is done with these conditions:

a. 737 mm (29 in) of mercury (DRY) barometric pressure.

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

c. 35 API rated fuel.

On a turbocharged and aftercooled engine, a change in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the 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 Fuel Setting And Related Information Fiche. BE SURE THAT THE AIR INLET OR EXHAUST DOES NOT HAVE A RESTRICTION WHEN MAKING A CHECK OF PRESSURE IN THE INLET MANIFOLD.

Pressure Test Location
(A) Plugs (1/4 in Std. pipe tap).

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

1U5470 Engine Pressure Group

This tool group has a gauge to read pressure in the inlet manifold. Special Instruction, Form No. SEHS8907 is with the tool group and gives instructions for its use.

Exhaust Temperature

Use the 1U8865 Infrared Thermometer to check exhaust temperature. The Operator's Manual, Form No. NEHS0510, for the 1U8865 Infrared Thermometer gives complete operating and maintenance instructions for this tool.

Air To Air Aftercooled Systems

Visual Inspection

Inspect all air lines, hoses and gasket connections at each oil change. Make sure the constant torque hose clamps are tightened to the correct torque. Check the truck manufacturer's specifications for the correct torque. Check welded joints for cracks and make sure all brackets are tightened in position and are in good condition. Use compressed air to clean cooler core blockage caused by debris or dust. Inspect the cooler core fins for damage, debris or salt corrosion. Use a stainless steel brush with soap and water to remove corrosion.

Show/hide table

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

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

The use of winter fronts or shutters is discouraged with air to air aftercooled systems. Winter fronts can only be used on truck models where tests have shown that the engine jacket water will overheat before the inlet manifold air temperature is excessive. On these trucks, sensors and gauges or alarms are installed to indicate engine operating conditions before excessive inlet manifold air temperatures are reached. Check with the truck manufacturer on winter front and shutter application.

Air System Restriction

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

Turbocharger Failure

Show/hide table

Pressure air can cause personal injury. When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes. The maximum air pressure must be below 205 kPa (30 psi) for cleaning purposes.

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

Show/hide table

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

Inlet Manifold Pressure

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

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

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

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

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

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

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

Aftercooler Core Leakage

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

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

Show/hide table

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

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

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

Tooling Installed
(1) Coupler. (2) Chain. (3) Dust plugs.

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

Show/hide table

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

Pressurize System
(5) Regulator and valve assembly.

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

Show/hide table

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

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

5. Inspect all connections for air leakage.

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

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

Show/hide table

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

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

Dynamometer Test

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

NOTE: Refer to special instructions Truck Performance Diagnostic Guide, Form No. SEBD0808 and Using The Caterpillar Performance Analysis Report (PAR) Program For On-Highway Truck Engines, Form No. SEHS8025 for more detailed instructions concerning preparation of the truck, proper use of the dynamometer and use of the Technical Information File microfiche.

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

Crankcase (Crankshaft Compartment) Pressure

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

8T2700 Indicator Group

The 8T2700 Indicator Group is used to check the amount of blowby. The test procedure is in Special Instruction, Form No. SEHS8712.

Compression

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

Cylinder Head

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

Valves

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

Valve Seat Inserts

Tools needed to remove and install valve seat inserts are in the 6V4805 Valve Insert Puller Group. Special Instruction, Form No. SMHS7935 gives an explanation for the procedure to remove the valve seat inserts. for easier installation, lower the temperature of the insert before it is installed in the head.

Valve Guides

Tools needed to remove and install valve guides are the 5P2396 Driver Bushing and 7S8859 Driver. The counterbore in the driver bushing installs the guide to the correct height. Use a 1P7451 Valve Guide Honing Group to make a finished bore in the valve guide after installation of the guide in the head. Special Instruction, Form No. SMHS7526 gives an explanation for this procedure. Grind the valves after the new valve guides are installed.

Checking Valve Guide Bores

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction, Form No. GMG02562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

Bridge Dowel

Use a 5P944 Dowel Puller Group with a 5P942 Extractor to remove the bridge dowels. Install a new bridge dowel with a 5P2406 Dowel Driver. This dowel driver installs the bridge dowel to the correct height.

Bridge Adjustment

When the head is disassembled, keep the bridges with their respective cylinders. Adjustment of the bridge will be necessary after the valves are ground or other reconditioning of the cylinder head is done. The bridge should be checked and/or adjusted each time the valves are adjusted. Use the procedure that follows to make an adjustment to the bridge.

NOTE: Valves must be fully closed.

Bridge Adjustment

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

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

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

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

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

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

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

Valve Clearance Setting

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

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 Clearance Check: Engine Stopped. If the measurement is outside this range, adjustment is necessary. See the chart for Valve Clearance Setting: Engine Stopped, and make the setting to the nominal (desired) specifications in this chart.

Valve Clearance Check

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

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

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

Valve Adjustment

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

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

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

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

Cylinder And Valve Location

Jake Brake Adjustment

NOTE: Slave piston lash is measured between the slave piston (both ends of the yoke) and the bridge.

Use the procedure that follows to make the adjustment:

Slave Piston Lash Adjustment (Typical Example)
(1) Screwdriver. (2) Adjustment screw. (3) Locknut. (4) Feeler gauges.

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

2. Loosen locknut (3). With screwdriver (1), turn adjustment screw (2) to make correct adjustment for cylinders 1, 3, and 5.

3. After each adjustment, tighten locknut (3) to a torque of 22 N·m (16 lb ft) and check the slave piston lash again.

NOTE: Be sure to check the lash with two feeler gauges (4) at the same time (one under each side of slave piston).

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

5. Make an adjustment to the slave piston lash for cylinders 2, 4, and 6.

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

Lubrication System

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

* Too Much Oil Consumption* Oil Pressure Is Low* Oil Pressure Is High* Too Much Bearing Wear* Increased Oil Temperature

Too Much Oil Consumption

Oil Leakage On Outside Of Engine

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

Oil Leakage Into Combustion Area Of Cylinders

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

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

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

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

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

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

Measuring Engine Oil Pressure

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

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

1U5470 Engine Pressure Group

This tool group has a gauge to read oil pressure in the engine. Special Instruction, Form No. 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 Manifold (Right Side Of Engine)
(1) Pressure test location.

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

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

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

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

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

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

Engine Oil Pressure Graph

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

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

Oil Pressure Is Low

Crankcase Oil Level

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

Oil Pump Does Not Work Correctly

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

Oil Filter Bypass Valves

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

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

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

Piston Cooling Tubes (Jets)

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

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

Oil Pressure Is High

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

Too Much Bearing Wear

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

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

Increased Oil Temperature

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

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

Cooling System

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

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

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

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

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

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

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

Testing The Cooling System

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

Test Tools For Cooling System

8T0470 Thermistor Thermometer Group

The 8T0470 Thermistor Thermometer Group is used in the diagnosis of overheating (engine hotter than normal) or overcooling (engine cooler than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Special Instruction, Form No. SEHS8446.

8T2700 Blowby/Air Flow Indicator Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The test procedure is in Special Instruction, Form No. SEHS8712.

6V3121 Multitach Group

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

9S8140 Cooling System Pressurizing Pump Group

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

Show/hide table

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

Checking Pressure Cap

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

Show/hide table

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.

Show/hide table

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

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

1. Remove the pressure cap from the radiator.

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

3. Look at the 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 module.

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

Testing Radiator And Cooling System For Leaks

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

Show/hide table

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

1. Remove the pressure cap from the radiator.

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

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

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

5. Check the radiator for outside leakage.

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

7. If you do not see any outside leakage and the pressure reading on the gauge is still the same after 5 minutes, the radiator and cooling system does 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

Water Temperature Connection
(1) Water temperature regulator housing. (2) Plug (1/2 in - 14 NPTF Thd.). (3) Plug (3/8 in - 18 NPTF Thd.).

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the 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. A temperature gauge of known accuracy can be connected at the location for plugs (2) or (3) to make this check. Also, the 8T0470 Thermistor Thermometer Group or the 2F7112 Thermometer and 6B5072 Bushing can be used.

Show/hide table

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

Water Temperature Gauge

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

Water Temperature Regulators

1. Remove the regulator from the engine.

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

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

4. Keep the water at the correct temperature for 10 minutes.

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

6. If the distance is less than 9.50 mm (.374 in), make a replacement of the regulator.

Belt Tension Chart

Basic Block

Piston Rings

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

Instructions For 1U6431 Gauge Group

Connecting Rods And Pistons

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

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

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

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

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

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

4. Tighten each nut 120° from the mark.

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

Connecting Rod And Main Bearings

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

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

Cylinder Block

1P3537 Dial Bore Gauge Group

The bore in the block for main bearings can be checked with the main bearing caps installed without bearings. Tighten the nuts that hold the caps to the torque shown in the Specifications module. Alignment error in the bores must not be more than 0.08 mm (.003 in). Special Instruction, Form No. SMHS7606 gives instructions for the use of 1P4000 Line Boring Tool Group for alignment of the main bearing bores. The 1P3537 Dial Bore Gauge Group can be used to check the size of the bores. Special Instruction, Form No. GMG00981 is with the group.

Projection Of Cylinder Liner

Check liner projection above top plate as follows:

1. Make certain that top plate (4) and the cylinder liner flange are clean. Install a new top plate gasket, but do not install liner seals when this check is made.

Holding Top Plate To Cylinder Block (Typical Example)
(1) 3H0465 Plate. (2) 1P2396 Puller Plate. (3) 2F0126 Seals (copper washers). (4) Top plate.

2. Use 3/4-16 NF bolts, 76.2 mm (3 in) long, with two 2F126 Seals (3) on each bolt to hold the top plate (4) to the cylinder block. Install two bolts with seals (3) on each side of the cylinder liner. Tighten the bolts evenly, in four steps; 14 N·m (10 lb ft), 35 N·m (25 lb ft), 70 N·m (50 lb ft) and then to 95 N·m (70 lb ft).

NOTE: To keep installation and removal of bolts and washers to a minimum as each liner is checked, install two bolts with washers on each side of each cylinder liner along the complete length of the top plate.

3. Use a 1P2396 Puller Plate (2), three 3H0465 Plates (1), 8B7548 Push-Puller (6), and two 3/4-16 NF bolts, 177.8 mm (7 in) long to hold the liner down.

4. Tighten the bolts evenly in four steps; 7 N·m (5 lb ft), 20 N·m (15 lb ft), 35 N·m (25 lb ft) and then to 70 N·m (50 lb ft). Distance from bottom edge of 8B7548 Push-Puller (6) to top plate must be the same on both sides of cylinder liner.

5. Use a 8T0455 Liner Projection Tool Group to measure liner projection. Special Instruction, Form No. SMHS7727 gives more information for the measurement procedures.

6. To zero dial indicator (5), use the back of 1P5507 Gauge with dial indicator (5) mounted in 1P2402 Gauge Body (7).

7. Liner projection must be 0.03 to 0.15 mm (.001 to .006 in). (Make the measurement to the top of the liner flange, not the inner ring). The maximum differential between high and low measurements made at four places around each liner is 0.05 mm (.002 in). The average projection of liners next to each other must not be more than 0.05 mm (.002 in). The maximum difference in the average projection of the cylinder liners under one cylinder head must not be more than 0.10 mm (.004 in).

Measuring Liner Height Projection (Typical Example)
(5) Dial indicator. (6) 8B7548 Push-Puller. (7) 1P2402 Gauge Body.

NOTE: If liner projection changes from point to point around the liner, turn the liner to a new position within the bore. If still not within specifications move liner to a different bore.

NOTE: When liner projection is correct, put a temporary mark on the liner and top plate so when seals and band are installed, the liner can be installed in the correct position.

The contact face of the cylinder block can be machined with use of the 8S3140 Cylinder Block Counterboring Tool Arrangement to adjust liner projection. Special Instruction, Form No. FM055228 is part of the cylinder block counterboring tool arrangement and gives information to use the tooling.

2W3815 and 5N0093 Stainless Steel Inserts are available for use after the cylinder block has been counterbored. Special Instruction, Form No. SMHS8222 has the correct installation procedure for the inserts.

Flywheel And Flywheel Housing

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

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

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

8T5096 Dial Indicator Group Installed

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

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

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

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

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

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

8T5096 Dial Indicator Group Installed

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

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

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

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

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

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

Checking Bore Runout Of The Flywheel Housing

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

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

8. Add lines I and II by columns

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

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

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

Graph For Total Eccentricity

Face Runout (Axial Eccentricity) Of The Flywheel

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

Checking Face Runout Of The Flywheel

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

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

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

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

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

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

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

4. The difference between the lower and higher measurements taken at all four points must not be more than:

Flywheel without BrakeSaver ... 0.15 mm (.006 in)

Flywheel with BrakeSaver ... 0.25 mm (.010 in)

Checking Flywheel Clutch Pilot Bearing Bore

5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed:

Flywheel without BrakeSaver ... 0.13 mm (.005 in)

Flywheel with BrakeSaver ... 0.25 mm (.010 in)

Vibration Damper

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

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

Vibration Damper
(1) Alignment marks.

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

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

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

3. Adjust the dial indicator to zero.

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

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 full charged. If the on-engine test shows a defect in a component, remove the component for more testing.

The service manual Testing And Adjusting Electrical Components, Form No. REG00636 has complete specifications and procedures for the components of the starting circuit and the charging circuit.

6V4930 Battery Load Tester

The 6V4930 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 12 Volt batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals, and a load adjustment knob on the front panel permits a current range up to a maximum of 700 amperes. The tester also has a thermometer to show when the safe operating temperature limit of the unit has been reached.

NOTE: Make reference to Special Instruction, Form No. SEHS8268 for more complete information for use of the 6V4930 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, Form No. 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, Form No. SEHS7734 for more complete information for use of the 6V7070 and 6V7800 Multimeters

Battery

Show/hide table

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 can 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 can damage, not only the charging unit, but also the regulator and other electrical components.

Use the 6V4930 Battery Load Tester, the 8T0900 Clamp-On Ammeter and the 6V7070 Multimeter to load test a battery that does not hold a charge when in use. See Special Instruction, Form No. SEHS8268 for the correct procedure and specifications to use.

Charging System

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

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

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

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

2. Cables between the battery, starter 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 (Delco-Remy)

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

5N5692 Alternator
(1) Ground terminal. (2) Pulley nut.

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

Alternator Pulley Nut Tightening (Delco-Remy)

Tighten nut that holds the pulley to a torque of 100 ± 10 N·m (75 ± 5 lb ft) with the tools shown.

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 (1-1/8 inch). (5) 8T5314 Socket.

Starting System

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

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

If the solenoid for the starter 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 reading of battery voltage shows the problem is in the motor. The motor must be removed for further testing. A zero reading on the multimeter shows that the solenoid contacts do not close. This is an indication of the need for repair to the solenoid or an adjustment to be made to the starter pinion clearance.

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

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

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

Pinion Clearance Adjustment (Delco-Remy)

When the solenoid is installed, make an adjustment of the pinion clearance. The adjustment can be made with the starter 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 starter motor, remove connector (1).

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

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

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

Pinion Clearance Adjustment
(4) 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 nut (4).

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

Pinion Clearance Adjustment (Bosch)

The solenoid position on the starting motor controls pinion clearance. If the solenoid position is correct, the pinion clearance is correct. Do the following procedure to adjust the solenoid position.

Solenoid Assembly
(1) Intermediate housing. (2) Solenoid mounting bracket. (3) Bolts. (X) 62.50 + 0.20 - 0.50 mm (2.46 + .008 - .020 in).

1. Check distance (X) between intermediate housing (1) and solenoid mounting bracket (2) with calipers.

2. If distance (X) is not correct, loosen bolts (3) and move the solenoid until distance (X) is correct. Bracket (2) has elongated holes.

3. Tighten bolts (3) to 7 to 10 N·m (5 to 7 lb ft) after the adjustment is correct.