Testing & Adjusting

Usage:

Troubleshooting

Reference: For Specifications with illustrations, make reference to Specifications For 3412 Industrial Engine, SENR4651. If the Specifications in SENR4651 are not the same as in the Systems Operation, Testing & Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.

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 Electronic Control System Engine Test Procedure Number P- or Diagnostic Code, see Electronic Troubleshooting, 3412 Industrial Engine, SENR4646.

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

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

1. Check Engine Light Is On While The Engine Is Running.

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

3. Engine Will Not Start.

4. Engine Mistires Or Runs Rough.

5. Engine Stalls At Low RPM.

6. Sudden Changes In Engine Speed.

7. Low Engine Power.

8. Loud Combustion Noise.

9. Fuel Consumption Too High.

10. Too Much Black Or Gray Smoke.

11. Too Much White Or Blue Smoke.

12. Engine Has Low Oil Pressure.

13. Engine Does Not Respond To Throttle Change.

14. Engine Speed Is Restricted To Less Than Top Engine Speed Limit.

15. Engine Overheating.

16. Engine Overcooling.

17. Coolant Leaks Outside Of Engine.

18. Coolant Leakage Inside Engine.

19. Fuel In Crankcase Oil.

NOTE: Electronic Control System Troubleshooting - see Electronic Troubleshooting, 3412 Industrial Engine, SENR4646.

Troubleshooting Problems

Problem 1: Check Engine Light Is On While the Engine Is Running

Probable Cause:

1. Low Engine Oil Pressure

Follow electronic control system engine Diagnostic Code 46.

2. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

3. Wiring Harness Fault Between The Electronic Control System Control Module And The Check Engine Lamp

Troubleshooting the wiring harness.

Problem 2: Engine Crankshaft Will Not Turn When Start Switch Is On

Probable Cause:

1. Problem Inside The Engine Prevents Crankshaft From Turning

If the crankshaft can not be turned after disconnecting any accessories remove the fuel injection nozzles and check for fluid in the cylinders while turning the crankshaft. If fluid in the cylinders is not the problem, the engine must be disassembled to check for other inside problems. Some of these inside problems are bearing seizure, and valves making contact with pistons.

Problem 3: Engine Will Not Start

NOTE: Follow Electronic Control System Engine Test Procedure P-109.

Probable Cause:

1. Starting Motor Turns Too Slow

The causes can be similar or the same as those that keep the crankshaft from turning. Check the items listed in Problem 2.

2. No Fuel To The Cylinders

Loosen a fuel injection line nut at the through the head adapter. With power switch(es) in the ON position and accelerator in the FUEL ON position, turn the crankshaft with the starting motor to be sure there is no fuel from the fuel injection pump. To find the cause for no fuel, follow Steps (a) through (c) until the problem is corrected.

a. Use the priming pump to make sure the fuel lines and fuel injection pump housing are full of fuel.

b. If you are not using a good quality of fuel at temperatures below -12°C (10°F), it is possible that the fuel in the system can "wax" (not have correct flow characteristics) and cause a restriction in the fuel system. Install a new fuel filter. It may be necessary to drain the complete fuel system and replace with a No. 1 grade of fuel.

c. Check for fuel supply line restriction by removing the fuel supply line for the fuel filter base. Put 35 kPa (5 psi) of air pressure to the fuel tank.

Show/hide table

NOTICE

Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.

If there is no fuel, or only a weak flow of fuel from the fuel supply line, there is a restriction in the fuel supply line and/or the fuel tank.

3. Low Quality Or Water In Fuel

Remove a small amount of fuel from the tank and check for water in the fuel. If there is water in the fuel, remove fuel from the tank until it is free of water and fill with a good quality fuel. For more information refer to Diesel Fuels And Your Engine, SEBD0717.

Change the fuel filter and "prime" (remove the air and/or low quality fuel from the fuel system) the fuel system with the fuel priming pump. If there is no water in the fuel, prime and start the engine by using an outside source of fuel. If the engine starts correctly using different fuel, remove all fuel from the tank and fill with good quality fuel. Prime the fuel system if necessary.

4. No Or Low Electrical Power Supply To Electronic Control System Control System

Follow Electronic Control System Engine Test Procedure P-109.

5. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

6. Optional Safety Shut Down System Is Preventing Engine Start

Follow check out procedure for safety shut down system, if used.

7. Wrong Fuel Injection Timing

Follow Electronic Control System Engine Test Procedure P-400.

8. No Air To Cylinders

Check for a plugged air cleaner element or blockage in the air lines. Refer to Restriction Of Air Inlet And Exhaust in the Testing & Adjusting section. Also, check inlet and exhaust valve operation.

Problem 4: Engine Misfires Or Runs Rough

NOTE: Follow Electronic Control System Engine Test Procedure P-107

Probable Cause:

1. Low Fuel Pressure

Change the primary and secondary fuel filters and check to make sure the fuel lines are not plugged or damaged. If the filters or lines are not the cause, a repair or replacement of the fuel transfer pump is needed.

2. Air In Fuel System

With air in the fuel system, the engine will normally be difficult to start, run rough, and release a large amount of white smoke. If the engine will not start, loosen a fuel injection line nut at the through the head adapter and crank the engine until fuel comes out. Tighten the fuel line nut. Start the engine. If the engine still does not run smooth or releases a large amount of white smoke, loosen the fuel line nuts one at a time at the through the head adapters until the fuel that comes out is free of air. Tighten the fuel line nuts. If the air can not be removed in this way, put 35 kPa (5 psi) of air pressure to the fuel tank.

Show/hide table

NOTICE

Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.

Check for leakage at the connections between the fuel tank and the fuel transfer pump. If leaks are found, tighten the connections or replace the lines. If there are no visual leaks, remove the fuel supply line from the tank and connect it to an outside fuel supply. If this corrects the problem, the suction line (standpipe) inside the fuel tank has a leak.

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

Check fuel lines for leaks, tighten fittings or replace lines.

4. Defective Fuel Injection Nozzle

Find a defective fuel injection nozzle by running the engine at the rpm where it runs rough. Loosen a fuel line nut, at the through the head adapter, enough to stop fuel supply to that cylinder. Each cylinder must be checked this way. If a cylinder is found where loosening of the nut makes no difference in the rough running, test the fuel injection nozzle for that cylinder. To test a fuel injection nozzle, remove the fuel injection nozzle from the engine and follow the procedure given in the Testing & Adjusting section.

5. 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 & Adjusting section for the correct specifications and procedure to check the plungers and lifters. Fuel pumps which are severely scored from debris can cause rough running, but fuel dilution usually occurs before horsepower is affected.

Low installation torque on the fuel pump retaining nut can cause misfire, rough running and low power.

6. Wrong Valve Lash

Check and make necessary adjustments as given in the Testing & Adjusting section. Inlet valve lash is 0.38 mm (.015 in) and exhaust valve lash is 0.76 mm (.030 in).

7. Bent Or Broken Push Rod

Follow the procedure given in the Disassembly and Assembly section to remove the push rods for replacement.

8. Cylinder Head Gasket Leakage

Inspect engine for signs of head gasket leakage and check for air bubbles in the engine coolant caused by combustion gases.

9. Low Quality Or Water In Fuel

Remove the fuel from the fuel tank. Follow the recommendations given in Diesel Fuels And Your Engine, SEBD0717.

10. Fuel Waxing

In cold weather operation this condition should be checked first. The fuel "cloud point" is the temperature at which wax begins to form in the fuel. If the atmospheric temperature is lower than the "cloud point" of the fuel, wax will form and plug the filter. Change the filter and drain the tank and complete fuel system. The replacement fuel must be of a better grade with a lower "cloud point".

11. Poor Electrical Power Supply To Electronic Control System

Follow Electronic Control System Engine Test Procedure P-110.

12. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

13. Poor Throttle Position Signal To Electronic Control System Control Module

Follow Electronic Control System Engine Diagnostic Code 34.

14. Poor Or Intermittent Engine Speed Signal

Follow Electronic Control System Engine Diagnostic Code 33.

15. Sticky Rack Operation

Follow Electronic Control System Engine Test Procedure P-502.

16. Sticky Timing Operation

Follow Electronic Control System Engine Test Procedure P-404.

Problem 5: Engine Stalls At Low RPM

NOTE: Follow Electronic Control System Engine Test Procedure P-106

Probable Cause:

1. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

2. Sticky Rack Operation

Follow Electronic Control System Engine Test Procedure P-502.

3. Low Fuel Pressure

4. Air In Fuel System

Show/hide table

NOTICE

Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.

5. Engine Accessories Over Loading The Engine

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

6. Defective Fuel Injection Nozzle

Defective fuel injection nozzles will normally cause the engine to misfire and run rough, but can cause too much smoke with engine still running smooth. Remove the fuel injection nozzles. Use the procedure given in the Testing & Adjusting section to test the fuel injection nozzles.

7. Defective Fuel Injection Pump

Problem 6: Sudden Changes In Engine Speed

NOTE: Follow Electronic Control System Engine Test Procedure P-105

Probable Cause:

1. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

2. Poor Throttle Position Signal To Electronic Control System Control Module

Follow Electronic Control System Engine Diagnostic Code 32.

3. Poor Or Intermittent Engine Speed Signal

Follow Electronic Control System Engine Diagnostic Code 33.

4. Poor Electrical Power Supply To Electronic Control System Control System

Follow Electronic Control System Engine Test Procedure P-110.

5. Sticky Rack Operation

Follow Electronic Control System Engine Test Procedure P-502.

Problem 7: Low Engine Power

NOTE: Follow Electronic Control System Engine Test Procedure P-900.

Probable Cause:

1. Low Quality Or Water In Fuel

Remove the fuel from the fuel tank. Follow the recommendations given in Diesel Fuels And Your Engine, SEBD0717.

2. Low Fuel Pressure

3. Fuel Temperature Is High

Fuel from the fuel transfer pump should not exceed 65°C (149°F).

4. Air In Fuel System

Show/hide table

NOTICE

Do not use more than 55 kPa (8 psi) of air pressure in the fuel tank or damage to the tank may result.

5. Leaks In Inlet Air System

Follow procedures in the Testing & Adjusting section to check inlet manifold pressure and aftercooler core leakage.

6. High Exhaust Back Pressure

Check exhaust system for restrictions.

7. Turbocharger Has Carbon Deposits Or Other Causes Of Friction

Inspect and repair turbocharger as necessary

8. Wrong Valve Lash

Check and make necessary adjustments as given in the Testing & Adjusting section. Inlet valve lash is 0.38 mm (.015 in) and exhaust valve lash is 0.76 mm (.030 in).

9. Poor Throttle Position Signal To Electronic Control System Control Module

Follow Electronic Control System Engine Diagnostic Code 32.

10. Defective Fuel Injection Nozzle

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

11. Defective Fuel Injection Pump

12. Engine Accessories Over Loading The Engine

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

13. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

14. Wrong Rack Position Sensor Calibration

Follow Electronic Control System Engine Test Procedure P-501.

15. Electronic Control System Measures Low Inlet Air Pressure

Follow Electronic Control System Engine Diagnostic Code 26.

16. Electronic Control System Measures Low Boost Pressure

Follow Electronic Control System Engine Diagnostic Code 25.

17. Wrong Boost Pressure Sensor Calibration

Follow Electronic Control System Engine Test Procedure P-600.

18. Sticky Rack Operation

Follow Electronic Control System Engine Test Procedure P-502.

Problem 8: Loud Combustion Noise

Probable Cause:

1. Low Quality Or Water In Fuel

Remove the fuel from the fuel tank. Follow the recommendations given in Diesel Fuels And Your Engine, SEBD0717.

2. Defective Fuel Injection Nozzle

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

3. Defective Fuel Injection Pump

4. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

Problem 9: Fuel Consumption Too High

NOTE: Follow Electronic Control System Engine Test Procedure P-900.

Probable Cause:

1. Low Quality Or Water In Fuel

Remove the fuel from the fuel tank. Follow the recommendations given in Diesel Fuels And Your Engine, SEBD0717.

2. Fuel System Leaks

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

3. Fuel And Combustion Noise (knock)

Check items listed in Problem Numbers 3, 6, and 7.

4. Wrong Rack Position Sensor Calibration

Follow Electronic Control System Engine Test Procedure P-501.

5. Defect In Fuel Injector(s)

Make reference to Problem 4.

Problem 10: 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 & Adjusting section to check inlet manifold pressure and aftercooler core leakage.

2. Defective Fuel Injection Nozzle

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

3. Wrong Rack Position Sensor Calibration

Follow Electronic Control System Engine Test Procedure P-501.

4. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

Problem 11: 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 fuel injection nozzles as needed to keep fuel out of the crankcase.

2. Engine Misfires Or Runs Rough

Check items listed in Problem Number 3.

3. Coolant In Combustion System

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

4. Failed Turbocharger Oil Seal

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

5. Worn Valve Guides

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

6. 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 section. NOTE: High wear at low hours is normally caused by dirt coming into the engine with the inlet air.

Problem 12: 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 engine oil filter or oil supply lines, etc.

3. Dirty Engine Oil Filter Or Engine Oil Cooler Core

Check the operation of bypass valve for the filter. Install new engine oil filter elements if needed. Clean or install new engine oil cooler core. Remove dirty oil 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 engine 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. Engine Oil Pump Suction Pipe Has A Defect.

Replacement of the pipe is needed.

7. Relief Valve For Engine Oil Pump Does Not Operate Correctly

Clean valve and housing. Install new parts as necessary.

8. Engine Oil Pump Has A Defect

Make a repair or replacement of the engine 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 Indicator

Replace oil pressure indicator

14. Electronic Control System Component Fault

Follow Electronic Control System Engine Diagnostic Code 46.

Problem 13: Engine Does Not Respond To Throttle Change

NOTE: Follow Electronic Control System Engine Test Procedure P-104.

Probable Cause:

1. Incorrect Customer Specified Parameters

Follow Electronic Control System Engine Test Procedure P-300 to determine specified parameters.

2. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

3. Loose, Broken, Or Misadjusted Throttle Linkage

Follow Electronic Control System Engine Test Procedure P-700 or P-701.

4. Poor Throttle Position Signal To Electronic Control System Control Module

Follow Electronic Control System Engine Diagnostic Code 32.

5. Sticky Rack Operation

Follow Electronic Control System Engine Test Procedure P-502.

6. Poor Electrical Power Supply To Electronic Control System

Follow Electronic Control System Engine Test Procedure P-110.

Problem 14: Engine Speed Is Restricted To Less Than Top Engine RPM Limit

NOTE: Follow Electronic Control System Engine Test Procedure P-103

Probable Cause:

1. Engine Has Low Oil Pressure

Check the items listed in Problem No. 12.

2. Loose, Broken, Or Misadjusted Throttle Linkage

Follow Electronic Control System Engine Test Procedure P-700 or P-701.

3. Incorrect Customer Specified Parameters

Follow Electronic Control System Engine Test Procedure P-300 to determine specified parameters.

4. Electronic Control System Component Fault

Follow Electronic Control System Engine Test Procedure P-200 to determine the diagnostic code.

5. Poor Throttle Position Signal To Electronic Control System Control Module

Follow Electronic Control System Engine Diagnostic Code 32.

6. Poor Electrical Power Supply To Electronic Control System

Follow Electronic Control System Engine Test Procedure P-110.

Problem 15: 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. Defective Temperature Indicator

A temperature indicator which does not work correctly will not show the correct temperature. If the temperature indicator shows that the coolant temperature is too hot but other conditions are normal, either install a indicator 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 Belt Tension Chart that is shown in Specification section.

5. Defective Hose(s)

Defective 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 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 (if equipped)

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. Defective 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 & Adjusting section for the procedure to test water temperature regulators.

8. Defective 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).

9. 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 defective 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.

10. 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 6.2 kPa (25 inches of H₂O). 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.

11. 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 defective 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 10.0 kPa (40 inches of H₂O). 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.

12. Fuel Injection Timing Not Correct

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

Problem 16: Engine Overcooling

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 can cause overcooling because of the low heat input of the engine. The installation of shutters helps to correct this condition.

3. Defective 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 engine has a light load. Also, coolant leaks around the thermostat, such as vent lines, can cause overcooling.

Problem 17: 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.

3. 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.

4. 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 18: 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 19: Fuel In Crankcase Oil

Probable Cause:

1. Loose Inner Fuel Injection Line Nut(s)

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

2. Fuel Injection Nozzle Leaks

Loose bleed screw or leaking bleed screw washer will cause fuel dilution in the crankcase. Check for defective bleed screw washers or damaged bleed screw washer face. Make sure the bleed screws are tightened to 2.7 ± 0.8 N·m (24 ± 7 lb in).

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

Fuel System

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

1. Not enough air for good combustion.

2. Oil leakage into combustion chamber.

3. Not enough compression.

Fuel System Inspection

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

1. Check the fuel level in the fuel tank. Be sure that the fuel tank is properly vented.

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

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 1/2 turn at each adapter in the valve cover base. Crank engine with the starting 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 receives fuel from the primary fuel filter. Fuel then moves through the ECM and the secondary fuel filters to the fuel injection pump.

To check the fuel transfer pump pressure, disconnect the fuel line (from the filter) at the fuel injection pump housing inlet. Install a tee at the inlet and connect the fuel line to the tee. Connect a pressure indicator to the tee and start the engine. Fuel is delivered to the fuel pump housing at approximately 414 kPa (60 psi) at full load speed.

If the fuel pressure is not up to 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 at specifications, 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 injection valve for that cylinder.

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

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

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

2. Orifice wear.

3. Dirty fuel injection nozzle screen.

Testing Fuel Injection Nozzles

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

Valve Opening Pressure Test

Flush The Nozzle

Tip Leakage Test

Orifice Restriction Test

Bleed Screw Leakage Test

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

Removal And Installation Of Fuel Injection Pumps

Removal Of Injection Pump

Put Rack At Zero Position
(1) Plug. (2) Governor control shaft.

1. Remove plug (1) from the timing pin hole on the fuel injection pump housing.

2. Install 4C9581 Rack Zero Pin with the flat end down in the hole that the plug was removed from.

3. Remove rack solenoid (BTM) and use the 4C9583 Fuel Pump Indicator to hold the rack against the rack zero pin.

4. Disconnect the fuel lines from the injection pumps.

5. Use the 8T5287 Wrench and 6V7050 Compressor Group to loosen the bushing that holds the fuel injection pump in the housing.

6. Install the 8S2244 Extractor on the threads of the injection pump. Pull the pump straight out of the bore.

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

Be careful when injection pumps are disassembled. Do not damage the surface on the plunger. The plunger and barrel for each pump 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 in the bore of the barrel.

Installation of 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.

Make reference to Fuel Injection Service, Removal Of Injection Pump for the correct procedure to center the fuel rack.

To install a fuel injection pump back into the housing bore, use the procedure that follows:

Fuel Pump Installation (Typical Illustration)
(3) Barrel. (4) Gear segment. (5) 8S2244 Extractor. (6) Bushing.

1. Put 8S2244 Extractor (5) on threads of injection pump.

2. Put groove of barrel (3) in alignment with slot of gear segment (4) (slot is on opposite side of gear segment teeth).

3. Look inside the bore of the injection pump housing to find the dowel. Put groove of the barrel in alignment with the dowel and put the injection pump straight down into the bore.

4. Push down on 8S2244 Extractor (5) with 6V7050 Compressor Group and install bushing (6) that holds the injection pump in the pump housing. If the pump is in the correct position, the bushing will turn into the threads of the injection pump housing with the fingers until it is even with the top of the housing (except for the pump that is in the position to fire). When bushing is installed correctly, tighten the bushing to 245 ± 15 N·m (180 ± 10 lb ft).

Show/hide table

NOTICE

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.

5. Remove the 4C9581 Rack Zero Pin from injection pump housing and install the plug back in the hole.

6. Move the governor control back to shut-off position. Check to be sure governor control moves freely between fuel-on and shut-off position.

NOTE: This check can only be done with the fuel injection pump OFF engine.

Check for the correct installation of injection pump with the engine stopped. Rack travel from the center position in the fuel-on direction can be checked with governor installed, but the governor and governor piston must be removed to check for full rack travel. Use 6V9128 Rack Position Tool Group and the chart that follows to check rack travel. Make reference to Fuel Rack Setting for installation of 6V9128 Rack Position Tool Group.

With the governor piston and valve removed, the total amount of fuel rack travel (from shut-off position to full load position) is approximately 20.32 mm (.800 in). If the pump is installed wrong (center tooth of gear segment is not in correct notch of fuel rack) fuel rack travel will be less than 20.32 mm (.800 in). The injection pump will have to be removed and then installed correctly.

Show/hide table

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 With Open Air Inlet (Typical Example)
(7) Air inlet.

a. Remove the air cleaners so that turbocharger air inlets (7) are open as shown.

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.

Stopping The Engine (Typical Example)

b. If a pump has been installed wrong and the engine does not run in a normal way, put a steel plate over the air inlet openings as shown to stop the engine.

Fuel Injection Lines

Fuel from the fuel injection pumps is sent through the fuel injection lines to the fuel injection valves.

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

The nuts that hold a fuel injection line to an injection valve and injection pump must be kept tight. Use a torque wrench and the 2P5494 Crowfoot Wrench to tighten the fuel line nuts to 40 ± 7 N·m (30 ± 5 lb ft).

Fuel Bypass Valve

The fuel bypass valve controls fuel pressure to the fuel injection pump at full speed to a pressure of 230 ± 35 kPa (33 ± 5 psi).

Finding Top Center Compression Position For No. 1 Piston

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

Locating Top Center (Right Side Of Engine)
(1) Timing bolt (in storage location). (2) Plug. (3) Bolt. (4) Cover.

1. Remove timing bolt (1), bolt (3) and cover (4).

2. Remove plug (2).

Location For 9S9082 Engine Turning Tool
(1) Timing bolt (installed). (5) 9S9082 Engine Turning Tool.

3. Install 9S9082 Engine Turning Tool (5) in the housing.

4. Hold timing bolt (1) against the flywheel through the hole from which plug (2) was removed.

5. Use a 1/2 inch drive ratchet and 9S9082 Engine Turning Tool (5) to turn the flywheel counterclockwise (as seen from the rear of the engine). Stop when the timing bolt goes into a threaded hole in the flywheel. If the timing bolt can be turned freely in the threaded hole in the flywheel, the No. 1 piston of the engine is on top center.

NOTE: If the hole in the flywheel is turned beyond the hole in the flywheel housing, turn the flywheel back (clockwise) a minimum of 30 degrees. Do Step 5 again. This will prevent timing error caused by play in the timing gears.

Cylinder And Valve Location

6. Remove the left front valve cover. Look at the valves of No. 1 cylinder. The valves will be closed if No. 1 piston is on the compression stroke. You should be able to move the rocker arms up and down with your hand. If No. 1 piston is not on the compression stroke, do the steps that follow.

7. Remove the timing bolt from the flywheel.

8. Turn the flywheel 360 degrees counterclockwise and install the timing bolt.

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

8T5300 Timing Indicator Group
(1) 8T5250 Engine Timing Indicator. (2) 5P7366 Cable Assembly. (3) 6V2197 Magnetic Transducer. (4) 5P7362 Cable. (5) 6V2199 & 6V3093 Transducer Adapters. (6) 8D4644 Fuse.

The 8T5300 Timing Indicator Group with an 8T5301 Diesel Timing Adapter Group, can be used to measure fuel injection timing for the engine.

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

When checking the dynamic timing on an engine that has a mechanical advance, Caterpillar recommends that the serviceman calculate and plot the dynamic timing specifications first on a worksheet like SEHS8140. See Special Instruction SEHS8580 for information required to calculate the timing curve.

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

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

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

Inspection of the plotted values will show if the fuel injection timing is within specification and if it is advancing correctly.

1. Make reference to Special Instruction SEHS8580 for complete instructions and calibration of the 8T5300 Timing Indicator Group.

Show/hide table

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

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

2. Disconnect fuel injection line (13) for No. 1 cylinder. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn the adapter onto the fuel pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in 5P7436 Adapter (9).

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

4. Move the end of fuel injection line (13) down on top of 5P7435 Tee Adapter (11). Hold fuel injection line (13) in place with 5P7437 Adapter (7) and tighten to a torque of no more than 40 N·m (30 lb ft).

Timing Hole Location
(14) Plug.

5. Remove plug (14) from timing hole in flywheel housing. Install 6V2199 or 6V3093 Transducer Adapter (5) into the timing hole and tighten just a small amount more than finger tight.

Transducer In Position
(3) 6V2197 Transducer.

6. Push 6V2197 Transducer (3) into 6V2199 or 6V3093 Transducer Adapter (5) until it makes contact with the flywheel. Pull it back out 1.5 mm (.06 in) and finger tighten the knurled locknut.

7. Connect the cables from the transducer to 8T5250 Timing Indicator (1). Calibrate and make adjustments. For calibration procedure, refer to Special Instruction SEHS8580.

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

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

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

Fuel System Adjustments (On Engine)

Camshaft Timing For Fuel Injection Pump

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

NOTE: A 1P3566 Hex Bit (9/16 inch) cut to a length of 25 mm (1.0 in) can be used to remove the plug from the front end of the injection pump housing.

Remove Timing Pin Plug.
(1) Timing Pin Plug.

2. Remove the plug at the front end of the fuel injection pump housing.

3. Install 6V2112 Timing Pin (end with taper) through the hole in the injection pump housing.

4. If timing is correct, the timing pin will go into the notch in the camshaft and the timing bolt will turn into the threaded hole in the flywheel. If timing is NOT correct, the timing must be changed.

NOTE: If timing is correct, BE SURE TO REMOVE TIMING PIN AND TIMING BOLT.

Access Cover To Automatic Timing Advance Unit
(2) Cover.

If timing was NOT correct, remove timing pin and use the procedure that follows to change the timing.

a. Remove access cover (2) to the four bolts of the automatic timing advance unit.

Automatic Timing Advance Unit
(3) Bolts. (4) Automatic timing advance unit.

b. BE SURE the timing pin is removed before you loosen the bolts. Loosen the four bolts (3) which hold automatic timing advance unit (4) on the fuel pump camshaft.

c. Tighten the bolts (3) with fingers until there is a small amount of friction (slight drag) between the retainer and the automatic timing advance unit (4). This friction will hold the unit against the timing gears. This prevents play (backlash) when gears are turned to the correct position.

d. Remove the timing bolt. Turn the flywheel until the timing pin will go into the groove in the injection pump camshaft.

e. With the timing pin installed, turn the flywheel clockwise (opposite the direction of engine rotation) a minimum of 30 degrees. The reason for this step is to be sure the backlash is removed from the timing gears when the engine is put on top center (TC).

f. Turn the flywheel in the direction of engine rotation until the No. 1 piston of the engine is on top center compression stroke. Then turn the timing bolt into the threaded hole in the flywheel.

g. Tighten bolts (3) to 25 N·m (20 lb ft). Then remove the timing pin from the injection pump housing.

h. Tighten bolts (3) to 230 ± 15 N·m (170 ± 11 lb ft). Then remove the timing bolt from the flywheel.

5. Turn the crankshaft two complete revolutions and check the timing again to see that timing pin will go into notch in camshaft with bolt in flywheel.

6. If timing is not correct, do the procedure of Steps b through h again.

NOTE: If timing is correct, BE SURE TO REMOVE TIMING PIN AND TIMING BOLT.

Engine Speed Measurement

9U7400 Multitach Group

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

Rack Position Sensor Calibration

1. Shut the engine off. Turn power off to the electronic control system control module.

Fuel Injection Pump Housing
(1) Rack Solenoid (BTM). (2) Cover. (3) Plug.

2. Remove plug (3), cover (2) and rack solenoid (BTM) (1) from the fuel injection pump housing.

Rack Timing Pin Installed
(A) 4C9581 Rack Zero Pin. (4) Rack servo.

3. Install 4C9581 Rack Zero Pin (A) in the top of the fuel injection pump housing. Make sure rack servo (4) is pushed toward the rear of the engine before the timing pin is installed.

Install Indicator Block
(B) 4C9583 Fuel Pump Indicator.

4. Install 4C9583 Fuel Pump Indicator (B) to hold rack bar against zero pin.

5. Disconnect the electronic control system data link connector (short pigtail out of the top of the electronic control system control module-P1/J1 connector) from the wiring harness and connect the 8T5275 Connector Cable to the electronic service tool.

6. Turn the power switch(es) to the ON position WITHOUT THE ENGINE RUNNING. Select the status display from the main menu that shows "Actual Rack Position" (refer to the Service Tool Special Instructions).

NOTE: Make sure the rack sensor is "stuck" to the magnet.

7. With the rack held back against the "zero pin", read the "Actual Rack Position" on the electronic service tool display.

a. If the "Actual Rack Position" reading is 9.50 ± 0.25 mm the rack position sensor is correctly calibrated.

b. If the "Actual Rack Position" reading is not 9.50 ± 0.25 mm the rack position sensor needs adjustment as follows:

8. Remove the wiring connectors from clip assembly. Do not disconnect any wiring at this time.

Adjustment Of Rack Position Sensor
(C) 4C9580 Socket. (5) Rack position sensor

9. Use 4C9580 Socket (C) and a 1/2 inch ratchet to loosen the locknut on rack position sensor (5).

10. Make sure the rack position sensor wiring is connected to the transducer module wiring.

11. With electrical power to the electronic control system control module, select the status display that has "Rack Position Sensor Calibration" from the main menu on the electronic service tool (refer to Special Instructions for the Service Tool used).

12. With the rack held back against the timing pin, turn the collar on the rack position sensor in or out until electronic service tool indicates the rack position sensor is calibrated.

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

14. Check the rack position calibration reading on the electronic service tool to make sure that the rack position sensor is still in calibration after tightening the locknut.

15. Turn power off to the electronic control system control module.

16. Install cover (2) on rack actuator housing. Make sure not to pinch a wire between the cover and housing.

17. Remove the rack zero pin and install plug (3) in top of the fuel injection pump housing.

18. Remove 4C9583 Fuel Pump Indicator (B) and push rack servo towards the rear of the engine.

19. Install the rack solenoid (BTM) (1).

NOTE: Make sure the lever of the solenoid engages correctly in the sleeve on the rack servo. If the lever is not engaged in the sleeve, the engine may overspeed or may not start.

20. Disconnect the electronic service tool from the electronic control system control module. Connect the electronic control system data link connector to the wiring harness.

Engine Speed Sensor Adjustment

Adjustment Of Engine Speed Sensor
(A) 4C9582 Crowfeet Wrench. (1) Engine speed sensor.

1. Use the 4C9582 Crowfoot Wrench (A) and a 3/8 inch drive ratchet and extension to loosen the locknut on engine speed sensor (1).

2. Turn engine speed sensor 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 the engine speed sensor.

3. Use the 4C9582 Crowfoot Wrench (A) and tighten the locknut on engine speed sensor 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.

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 7.5 kPa (30 inches of H₂O).

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 6.7 kPa (27 inches of H₂O).

Measurement Of Pressure In Inlet Manifold

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

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

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

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

c. 35 API rated fuel

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

A difference in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. If the fuel is rated below 35 API, the pressure in the inlet manifold can be more than given in the TMI (Technical Marketing Information) or Fuel Setting And Related Information Fiche. Be Sure That The Air Inlet And Exhaust Do Not Have A Restriction When Making A Check Of Pressure In The Inlet Manifold.

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

Remove the plug on the aftercooler housing to measure inlet manifold pressure.

1U5470 Engine Pressure Group

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

Turbocharger

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

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

If end play is more than the maximum end play rebuild or replace the turbocharger. End play less than the minimum end play could indicate carbon build up on the turbine wheel and the turbocharger should be disassembled for cleaning and inspection.

Checking Turbocharger Rotating Assembly End Play
(Typical Example)

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

NOTE: Care must be taken not to cock the shaft or a false reading will be obtained.

Exhaust Temperature

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

Crankcase (Crankshaft Compartment) Pressure

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

8T2700 Indicator Group

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

Compression

An engine that runs rough can have a leak at the valves, or have valves that need adjustment. Use the test that follows for a fast and easy method to find a cylinder that has low compression, or does not have good fuel combustion. Find the speed that the engine runs the roughest, and keep the engine at this rpm until the test is finished. Loosen the fuel line nut at a fuel injection pump to stop the flow of fuel to that cylinder. Do this for each cylinder until a loosened fuel line is found that makes no difference in engine performance. Be sure to tighten each fuel line nut after the test before the next fuel line nut is loosened. This test can also be an indication that the fuel injection is wrong, so the cylinder will have to be checked thoroughly. Removal of the head and inspection of the valves and valve seats is necessary to find those small defects that do not normally cause a problem. Repair of these problems is normally done when reconditioning the engine.

Cylinder Head

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

Valves

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

Valve Seat Inserts

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

Valve Guides

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

Checking Valve Guide Bore

Use the 5P3536 Valve Guide Gauge Group to check the bore of the valve guides. Special Instruction GMGO2562 gives complete and detailed instructions for use of the 5P3536 Valve Guide Gauge Group.

5P3536 Valve Guide Gauge Group

Bridge Dowel

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

Bridge Adjustment

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

Bridge Adjustment

NOTE: Valves must be fully closed.

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

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

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

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

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

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

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

Valve Lash Setting

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

Valve Lash Check: Engine Stopped

Exhaust ... 0.69 to 0.84 mm (.027 to .033 in)

Inlet ... 0.30 to 0.46 mm (.012 to .018 in)

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

Valve Lash

NOTE: Inlet and exhaust valve lash adjustments should be made at the first recommended oil change.

Valve Lash Setting: Engine Stopped

Exhaust ... 0.76 mm (.030 in)

Inlet ... 0.38 mm (.015 in)

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

Valve Adjustment (Typical Illustration)

Cylinder And Valve Location

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

2. Make an adjustment to the valve lash on the inlet valves for cylinders 1, 3, 4, 6, 7 and 12. Make an adjustment to the valve lash on the exhaust valves for cylinders 1, 4, 5, 8, 9 and 12.

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

4. Remove the timing bolt and turn the flywheel 360 degrees in the direction of engine rotation. This will put No. 11 piston at top center (TC) on the compression stroke. Install the timing bolt in the flywheel.

5. Make an adjustment to the valve lash on the inlet valves for cylinders 2, 5, 8, 9, 10 and 11. Make an adjustment to the valve lash on the exhaust valves for cylinders 2, 3, 6, 7, 10 and 11.

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

7. Remove the timing bolt from the flywheel when all valve lash are correct.

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

Oil Leakage Into Combustion Area of Cylinders

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

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

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

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

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

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

Measuring Engine Oil Pressure

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

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

1U5470 Engine Pressure Group

This tool group has a indicator to read oil pressure in the engine. Special Instruction SEHS8524 is with the tool group and gives instructions for the test procedure.

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

Oil Manifold
(1) Pressure test location.

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

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

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

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

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

Engine Oil Pressure Graph

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

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

Oil Pressure Is Low

Crankcase Oil Level

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

Engine Oil Pump Does Not Work Correctly

The inlet screen of the supply tube for the engine 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 engine oil pump will also cause cavitation and loss of oil pressure. If the bypass valve for the engine oil pump is held in the open (unseated) position, the lubrication system can not get to maximum pressure. Engine oil pump gears that have too much wear will cause a reduction in oil pressure.

Engine Oil Filter Bypass Valves

If the bypass valve for the engine oil filter is held in the open position (unseated) because the engine 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 engine oil filter with an oil change to be sure that no more debris makes the bypass valve stay open.

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

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

Piston Cooling Tubes (Jets)

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

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

Oil Pressure Is High

Oil pressure will be high if the bypass valve for the engine 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. A broken oil passage can also be the cause.

If the indicator for oil pressure shows enough oil pressure, but a component is worn because it 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 and coolant passages of the engine oil cooler. If the engine 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 engine oil cooler has a restriction.

Also check the engine oil cooler bypass valve to see if it is held in the open position (unseated). This condition will let the oil through the valve instead of the engine 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 To The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

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

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

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

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

Testing The Cooling System

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

Test Tools For Cooling System

4C6500 Digital Thermometer Group

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

8T2700 Blowby/Air Flow Indicator Group

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

9U7400 Multitach Group

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

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.

Filler Cap and Pressure Relief Valve

Typical Pressure Relief Valve System
(1) Pressure relief valve. (2) Stud for filler cap.

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

9S8140 Cooling System Pressurizing Pump Group
(3) Release valve. (4) Adapter. (5) Hose.

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

Show/hide table

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

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

2. Inspect the filler 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.

Use the procedure that follows to pressure check the cooling system.

1. Make sure the coolant level is above the top of the radiator core.

2. Install and tighten the filler cap.

3. Remove hose (5) from adapter (4).

4. Remove the pressure test plug for the radiator top tank.

5. Install the end of hose (5) in the hole for the pressure test plug as shown.

6. Operate the pump until the pointer on the pressure indicator no longer increases. The highest pressure indication on the indicator is the point that the relief valve opens. The correct pressure that makes the relief valve open is 105 to 125 kPa (15 to 18 psi).

7. If the relief valve does not open within pressure specification, replacement of the relief valve is necessary.

8. If the relief valve is within specifications, check the radiator for outside leakage.

9S8140 Pump Group Installed

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

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

Show/hide table

If a pressure indication is shown on the indicator, to avoid personal injury push release valve (3) to release all pressure in the system before removal of hose (5) from the radiator.

11. Remove hose (5) from radiator test pressure location.

12. Install plug in pressure test location.

Indicator For Water Temperature

Water Temperature Connection
(1) Sending unit.

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the indicator for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place cannot be found where there is coolant leakage, check the accuracy of the indicator for water temperature. A temperature indicator of known accuracy can be connected at the location for sending unit (1) to make this check. Also, the 4C6500 Digital 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.

Start the engine and run it until the temperature is at the desired range according to the test indicator or thermometer. If necessary, put a cover over part of the radiator or cause a restriction of the coolant flow. The reading on the indicator for water temperature must be the same as the test indicator or thermometer within the tolerance range in the chart in specifications, 3412 Industrial Engine, SENR4651.

Water Temperature Regulators

1. Remove the regulator from the engine.

2. Heat water in a pan until the temperature is 92°C (197°F). Move the water around in the pan to make it all the same temperature.

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

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

5. After ten minutes, remove the regulator and immediately measure the distance the regulator has opened. Refer to the Specification module for the correct opening distance.

Belt Tension Chart

Basic Block

Piston Rings

This engine has piston grooves and rings both conventional and of the KEYSTONE (taper) design. The 1U6431 Keystone Piston Ring Groove Gage Group is available to check the top two ring grooves in the piston. For correct use of the gage group see the instruction card that is with the gage group.

The 5P3519 Piston Ring Groove Gauge is available for checking the oil control ring groove. For instructions on the use of the gauge, refer to Guideline For Reusable Parts, Pistons SEBF8049.

Instructions For 1U6431 Keystone Piston Ring Groove 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 bolts in the step sequence that follows:

1. Put engine oil on bolt threads and contact surfaces of nut and cap.

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

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

4. Tighten each nut 120 degrees from the mark.

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

Connecting Rod And Main Bearings

Connecting rod bearings are available with 0.64 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 0.64 mm (.025 in) larger outside diameter than the original size bearings.

Cylinder Block

1P3537 Dial Bore Gauge Group

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

Cylinder Liner Projection

(1) Bolt. (2) Steel washer. (3) Fabric washer.

Install larger diameter washers (4) and (5) under bolts marked "X".

Install smaller diameter washers (6) and (7) under remaining two bolts.

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

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

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

4. The cylinder liner specifications are as follows:

Liner projection ... 0.025 to 0.152 mm (.0010 to .0060 in)

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

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

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

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

6. If the liner projections are all below the specifications or low in the range, 0.025 mm (.0010 in) or 0.051 mm (.0020 in), try using a thinner spacer plate. These plates are 0.076 mm (.0030 in) thinner than the regular plate and they will increase the liner projection, thus increasing the fire ring crush. Use these spacer plates to compensate for low liner projections that are less than 0.076 mm (.0030 in) or if the inspection of the top deck reveals no measurable damage directly under the liner flanges, but the average liner projection is less than 0.076 mm (.0030 in).

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

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

8. When the engine is ready for final assembly, the O-ring seals, cylinder block and upper filler band must be lubricated before installation. Refer to the Disassembly And Assembly Manual for the proper procedure to install the cylinder liners.

Flywheel And Flywheel Housing

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

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 0.00 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 runout (axial eccentricity) of the flywheel housing.

Bore Runout (Radial Eccentricity) Of The Flywheel Housing

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

8T5096 Dial Indicator Group Installed

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).

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

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

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

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

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 & 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.

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

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 range marked "Not Acceptable", the flywheel housing must be changed.

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.

2. Set the dial indicator to read 0.0 mm (.00 in).

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

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible face runout (axial eccentricity) of the flywheel.

Checking Face Runout Of The Flywheel

Bore Runout (Radial Eccentricity) Of The Flywheel

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

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

2. Set the dial indicator to read 0.0 mm (.00 in).

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

4. The difference between the lower and higher measurements taken at all four points must not exceed the maximum permissible bore runout (radial eccentricity) of the flywheel.

Checking Flywheel Clutch Pilot Bearing Bore

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

Electrical System

Test Tools For Electrical System

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

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

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

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

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

8T0900 AC/DC Clamp-On Ammeter

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

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

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

6V7070 Heavy-Duty Digital Multimeter

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

NOTE: Make reference to Special Instruction, SEHS7734 for more complete information for use of the 6V7070 Multimeter.

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 4C4911 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, SEHS9249 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 percent (1.225 Sp Gr) fully charged and held tightly in place. The battery holder must not put too much stress on the battery.

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

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

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

Alternator

3T1888 Alternator

Alternator Regulator Adjustment

When an alternator is charging the battery too much or not enough, an adjustment can be made to the charging rate of the alternator.

1. Remove the covers from the end of the alternator to get access to the voltage regulator.

Regulator Adjustment
(1) Potentiometer adjustment screw. (2) Transistor pins.

2. Remove the rubber from the potentiometer so that the small screw can be seen.

3. Connect a voltmeter across the batteries to measure the regulation of the voltage.

NOTE: The batteries must have a good charge for this measurement.

4. Operate the alternator at medium speed for 30 seconds and take a measurement of the voltage. The voltage must be 27.5 ± 1.0 volts. Turn the small screw counterclockwise to get less voltage output and clockwise to get more voltage output.

5. After the adjustment has been made, Put a thin layer of 3S6252 Silicone Rubber Sealant on the adjustment screw and install the covers.

NOTE: Make sure the location of the wires to the voltage regulator is not over the transistor pins. The transistor pins could make holes in the insulation for the wires and cause a short circuit.

9G9538 Alternator

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

6T7223 Alternator

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

Alternator Pulley Nut Tightening

Tighten the nut that holds the pulley to specifications given in the Specification Module.

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 in). (5) 8T5314 Socket.