3406B DIESEL TRUCK ENGINE Caterpillar


Testing And Adjusting

Usage:

Brakesaver Troubleshooting

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

Pull-Down RPM Check

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

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

2. Make a record of the engine rpm.

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

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

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

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

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


NOTICE

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


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

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

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

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

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

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

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

BrakeSaver Troubleshooting Problem List

1. BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The MANUAL Position.
2. BrakeSaver Does Not Give Full Braking Force With The Mode Selector Switch In The AUTOMATIC-MANUAL Position.
3. BrakeSaver Oil Temperature Is Too High.
4. BrakeSaver Does Not Turn OFF Or Become Empty.
5. Oil Leakage From The Flywheel Housing.
6. Oil Leakage From The Clutch Housing Or Transmission.


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

Fuel System

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

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

Fuel System Inspection

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

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

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

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

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

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

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

Fuel Transfer Pump

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

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


Fuel Lines
(1) Fuel inlet.

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

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

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

Checking Engine Cylinders Separately

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

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

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

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

1. Steel wire brushing of nozzle tip.
2. Orifice wear.


NOTICE

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


Fuel Injection Lines


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

Clamp location dimensions are in reference to a vertical line through the number one injection pump.

Fuel Injector Testing

Testing of the injectors must be done off the engine. Use 5P4150 Nozzle Testing Group. For use of the 5P4150 Nozzle Testing Group, refer to Special Instructions, Form No. SEHS7292.

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

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

------ WARNING! ------

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

--------WARNING!------


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

The nuts that hold a fuel injection line to an injection nozzle and injection pump must be tightened to the correct torque. If the nut is loose, fuel will leak from the connection. If the nut is tightened too tight, the inside diameter of the line will become smaller and cause a restriction to the flow of fuel in the line. Use a torque wrench and a 5P0144 Fuel Line Socket to tighten the fuel injection line nuts to 42 ± 7 N·m (31 ± 5 lb ft).

------ WARNING! ------

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

--------WARNING!------

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

Earlier engines use clamps with rubber dampers. Tighten these clamps to a torque of ... 10 N·m (8 lb ft)

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

Checking the Plunger and Lifter of an Injection Pump

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

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


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

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

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

Removal and Installation of Fuel Injection Pumps

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

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

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


Adjustment of 6V7050 Compressor Group
(A) 6V7015 Clamp. (B) Bracket assembly. (C) 4B2046 Nut. (D) 8T937 Nut. (E) 2N3476 Screw.

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

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

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

4. Install and tighten nut (D).

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

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

Removal of Fuel Injection Pumps


NOTICE

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


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


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

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


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

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


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

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

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

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


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

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

------ WARNING! ------

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

--------WARNING!------

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

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


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

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


Fuel Injection Pump Housing
(9) 8S2244 Extractor.

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

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

Installation of Fuel Injection Pump


NOTICE

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


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


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

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

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

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

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


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

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

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


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

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

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


NOTICE

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


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

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


NOTICE

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


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

------ WARNING! ------

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

--------WARNING!------

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

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

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

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


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

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


Illustration 1. Correct installation in full load position.

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

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


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

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


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

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

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


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

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

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

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


NOTICE

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



Turbocharger Air Inlet Opening

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

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

------ WARNING! ------

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.

--------WARNING!------

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


Stopping the Engine

Finding Top Center Compression Position for No. 1 Piston

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

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


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

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


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

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


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

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

3. Remove the front valve cover from the engine.


Checking No. 1 Intake and Exhaust Valves

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

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


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

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


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

------ WARNING! ------

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

--------WARNING!------

When checking the dynamic timing on an engine without a mechanical advance, Caterpillar recommends that the serviceman calculate and graph the dynamic timing on a worksheet like Form No. SEHS8140. These worksheets are available in pads of 50 sheets, order one Form No. SEHS8140. See Special Instruction Form No. SEHS8580, for information required to calculate the timing curve.

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

Inspection of the plotted value will show if the timing is within specifications. See Special Instruction, Form No. SEHS8580 for information required to calculate the timing.

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

2. Make reference to Operation Instructions inside the lid of the 8T5300 Timing Indicator (1) or Special Instruction Form No. SEHS8580 for complete instructions and calibration.

------ WARNING! ------

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

--------WARNING!------


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

3. Loosen all fuel line clamps that hold No. 1 fuel injection line, and disconnect fuel injection line (13) for the No. 1 cylinder at the fuel injection pump. Slide the nut up and out of the way. Put 5P7436 Adapter (9) in its place and turn adapter (9) onto the fuel pump bonnet until the top of the bonnet threads are approximately even with the bottom of the "window" in the adapter.

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

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

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


Transducer In Position
(3) TDC magnetic transducer. (5) Transducer adapter.

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

8. Connect the cables from the transducers to Engine Timing Indicator (1). Calibrate and make adjustments. For calibration procedure, make reference to Special Instruction Form No. SEHS8580.

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

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


Front Of Engine
(14) Access cover for governor and fuel pump drive group.

11. Stop the engine and remove cover (14).


Automatic Timing Advance Unit (Governor And Fuel Pump Drive Group)
(15) Locknut. (16) Screw. (17) Locknut. (18) Setscrew.

Steps 12 through 15 are for earlier timing advance units 7FB1-Up and 4MG1-4MG3599.

12. To adjust the speed where the fuel injection timing starts to advance, loosen locknut (15) and turn screw (16). Turn screw (16) clockwise to increase the speed where the timing advance starts. One turn of screw (16) will change START speed approximately 50 rpm. Tighten locknut (15) to a torque of 70 ± 15 N·m (50 ± 11 lb ft).


Adjust Speed Where Advance Stops
(19) 6V2106 Tool Group.

NOTE: If the speed where timing advance starts is adjusted, the speed where the automatic timing advance stops should also be adjusted.

13. To adjust the speed where the fuel injection automatic timing advance stops, loosen locknut (17) and turn setscrew (18). Turn setscrew (18) clockwise to decrease the stop speed. One turn of setscrew (18) will change STOP speed approximately 30 rpm. Tighten locknut (17) to a torque of 2.25 ± 0.25 N·m (20 ± 2 lb in). 6V2106 Tool Group (19) [part of 6V6070 Governor Adjusting Tool Group] can be used to make this adjustment.

14. After each adjustment, install cover (14) and recheck the automatic timing advance with the 8T5300 Timing Indicator Group.

15. If the automatic timing advance unit cannot be adjusted to operate within the correct range, or the operation of the unit is not smooth, replace the automatic timing advance unit (governor and fuel pump drive group).


Later Automatic Timing Advance Unit
(15) Locknut. (16) Screw. (18) Setscrew-located inside of screw (11).

Steps 16 through 20 are for later timing advance units 4MG3600-Up, 5KJ1-Up and 3ZJ1-Up.

16. If the adjustments are being make because of an engine horsepower rating change of for replacement of parts, start with an initial setting as follows:

a. Adjustment screw (16) must extend out from the retainer approximately 27.9 mm (1.10 in).

b. Setscrew (18) must be below the end of screw (11) approximately 17.78 mm (.700 in) on an engine with 11° timing advance and 19.05 mm (.750 in) on an engine with 10° timing advance.

17. To adjust the speed where the fuel injection timing starts to advance, loosen locknut (15) and turn screw (16). Turn screw (16) clockwise to increase the speed where the timing advance starts. Tighten locknut (15) to a torque of 70 ± 15 N·m (50 ± 11 lb ft).

NOTE: If the speed where timing advance starts is adjusted, the speed where the automatic timing advance should also be adjusted.

18. To adjust the speed where the fuel injection automatic timing advance stops, loosen locknut (17) and turn setscrew (18) clockwise to decrease the stop speed. Tighten locknut (17) to a torque of 2.25 ± 0.25 N·m (20 ± 2 lb in). 6V2106 Tool Group (19) [part of 6V6070 Governor Adjusting Tool Group] can be used to make this adjustment.

19. After each adjustment, install cover (14) and recheck the automatic timing advance with the 8T5300 Timing Indicator Group.

20. If the automatic timing advance unit cannot be adjusted to operate within the correct range, or the operation of the unit is not smooth, repair or replace the automatic timing advance unit (governor and fuel pump drive group).

Checking Engine Timing By Timing Pin Method 7FB1-Up, 4MG1-4MG3599

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


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

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


Timing Pin Installed
(2) 6V4186 Timing Pin.

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


NOTICE

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


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


Front Of Engine
(3) Access cover for automatic timing advance (governor and fuel pump drive group).

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

a. Remove cover (3).


Automatic Timing Advance Unit (Governor And Fuel Pump Drive Group).
(4) Bolts.

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

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

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

e. Tighten four bolts (4) to a torque of 55 ± 7 N·m (41 ± 5 lb ft). Remove the timing bolt from the flywheel and timing pin (2) from the fuel injection pump housing.

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

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

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

Engine Timing By Timing Pin Method 4MG3600-Up, 5KJ1-Up, 3ZJ1-Up

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

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


Front Of Engine (Typical Example)
(1) Access cover for automatic timing advance (governor and fuel pump drive group).

2. Remove timing advance cover (1).

3. Loosen nuts (3) and remove retainer (2) and the flyweight spring from the timing advance unit. Make sure that the flyweight spring does not fall out and get lost.


Timing Advance Unit
(2) Retainer. (3) Nuts. (4) Bolts.

NOTE: Do not loosen the locknuts and adjustment screws in the end of retainer (2). If the adjustment screws are moved from their original settings, the dynamic engine timing must be set by using the 8T5300 Timing Indicator Group after the static timing pin procedure is completed.

4. Loosen bolts (4) that hold the timing advance unit together.

5. Tighten bolts (4) to a torque of 2.2 ± 0.1 N·m (20 ± 1 lb in). This puts a slight clamping force on the fuel pump drive gear to hold it in position. Also, the fuel pump camshaft can be turned or held in position separate from the engine crankshaft. The drive gear is allowed to slip.


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

6. Remove plug (5) from the fuel injection pump housing.


Timing Pin Installed
(6) 6V4186 Timing Pin.

7. With No. 1 piston 45° before Top Center, slowly rotate the crankshaft counterclockwise (as seen from the flywheel end of the engine) until timing pin (6) goes into the slot in the fuel pump camshaft and the timing bolt can be installed in the timing hole in the flywheel.


Install Holding Tool
(3) Nut. (7) 1U8271 Holding Tool.

8. Install the 1U8271 Holding Tool (7) and push the timing advance unit piston back as follows:

a. Turn the knurled nuts on the holding tool out until each stud is 6.4 mm (.25 in) below the surface of the nut.

b. Put holding tool (7) in position on the cap screws that hold retainer (2). Install and tighten nuts (3) finger tight. Make sure that the four tangs on the loose inner ring of the holder tool are positioned at the corners of the four flyweights and flyweights are free to move.

c. Tighten the four large knurled nuts evenly by hand until a positive stop is felt. No external component contact can be seen. The positive stop is the timing advance piston making contact at the bottom of its travel. This step makes sure that the timing advance unit is in its most retarded timing position.


Tighten Drive Bolts And Remove Tooling
(4) Bolts.

9. Tighten the four bolts (4) to a torque of 55 ± 7 N·m (41 ± 5 lb ft).

10. Remove holding tool from the automatic timing advance unit.

11. Remove the timing pin bolt from the flywheel and timing pin (6) from the fuel injection pump housing.

12. Install the flyweight spring and retainer (2) on the timing advance unit. Make sure the spring is in its correct position and tighten the four nuts to hold the retainer in position.

13. Install cover (1) on the timing gear housing and plug (5) in the fuel injection pump housing.

14. If necessary, check the dynamic timing of the engine with the 8T5300 and 8T5301 Tool Groups. Make reference to Special Instructions, Form No. SEHS8580, for the correct installation and operation of the tool groups. Also, see Checking Engine Timing With 8T5300 Timing Indicator Group And 8T5301 Diesel Timing Adapter Group for the procedure to check the dynamic timing of the engine.

Fuel Setting Procedure


6V6070 Governor Adjusting Tool Group

NOTE: If the 8T1000 Electronic Position Indicator Group is used, make reference to Special Instruction Form No. SEHS8623 for information on the use of the tool group.

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


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

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


Indicator And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 6V6109 Bracket Assembly. (5) 2A0762 Bolt [1/4-20 NC × 15.88 mm (.625 in)]. (6) 8H9178 Ground Body Bolt [1/4-20 NC × 25.4 mm (1.00 in)]. (7) 5P4814 Collet. (8) 6V6106 Dial Indicator.

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

2. Install the rack position indicator as follows:

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


Slot In Fuel Injection Pump Rack
(9) Slot.

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

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

d. Be sure the indicator arm moves freely.

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

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

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

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

3. Install the rack position probe as follows:

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

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

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

d. Be sure the indicator arm moves freely.

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

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

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

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


Probe And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 6V6109 Bracket Assembly. (5) 2A0762 Bolt [1/4-20 NC × 15.88 mm (.625 in)]. (6) 8H9178 Ground Body Bolt. [1/4-20 NC × 25.4 mm (1.00 in)]. (7) 5P4814 Collet. (A) 8T1002 Probe.

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


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

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

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

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


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

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


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

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


Fuel Rack Against Timing Pin

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

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

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


6V7941 Compressor Assembly
(13) Rod.

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

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


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

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


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

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

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

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

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


NOTICE

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


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

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

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

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

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

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

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

20. See the Fuel Setting And Related Information Fiche for the correct static full torque setting. On later engines the full torque static setting is on the Engine Information Plate.

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


Adjustment Of Governor
(17) Adjustment screw cover.

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

Since "desired setting" is lower than "actual reading," turn the adjusting screw in (clockwise) approximately 1 1/8 turns. Recheck the new setting and readjust if necessary.

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

The "desired setting" is higher than the "actual reading." Turn the adjusting screw out (counterclockwise) approximately 1 1/8 turns. Recheck the new setting and readjust if necessary.

The "desired setting" is lower than the "actual reading." Turn the adjusting screw in approximately 2 7/8 turns.

The "desired setting" is higher than the "actual reading." Turn the adjusting screw out approximately 2 7/8 turns.


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


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

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

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

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

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

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

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

Fuel Ratio Control And Governor Check (Earlier Engines)

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

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

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

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

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

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

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

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

8. Release the governor control shaft and linkage.


Remove Boost Line
(1) Air Line.

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

------ WARNING! ------

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

--------WARNING!------

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

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

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

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

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

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

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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

Fuel Ratio Control Adjustment (All Engines Except CARB Approved) For Use With Earlier Engines

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

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

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


Remove Boost Line
(1) Air line.

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


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

NOTE: On earlier engines, Step 4 must be done to make sure that stop (5) does not contact retainer (8). Later engines do not have stop (5) and nut (6). Do not add these parts when the fuel ratio control is repaired.


Adjustment Components
(4) Nut. (5) Stop. (6) Nut. (7) Valve extension. (8) Retainer.

4. Loosen nut (4) and turn stop (5) in (clockwise) until the stop makes contact with the shoulder on retainer (8). Now turn the stop out (counterclockwise) two complete turns and tighten nut (4).

------ WARNING! ------

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

--------WARNING!------

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

6. Activate the fuel ratio control by pushing in on valve extension (7).


Hold Retainer In Position

7. Hold retainer (8) in position and loosen nut (6). This keeps the fuel ratio control diaphragm from turning when nut (6) is loosened or tightened.

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


Adjustment Of Fuel Ratio Control

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

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

10. After the correct adjustment has been made, tighten nut (6). Check the dynamic fuel ratio control setting again.

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

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

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

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

14. Stop the engine.

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

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

17. Remove the rack position indicator tooling.

Fuel Ratio Control Adjustment (CARB Approved Engines) For Use With Earlier Engines

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

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

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


Remove Boost Line
(1) Air Line.

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


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


Adjustment Components
(4) Nut. (5) Stop. (6) Nut. (7) Valve extension. (8) Retainer.

4. Make an adjustment of the preload as follows:

a. Loosen nut (4) and turn stop (5) out (counterclockwise) 2 or 3 complete turns.

------ WARNING! ------

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

--------WARNING!------

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

c. Activate the fuel ratio control by pushing in on valve extension (7).

d. Start at 900 rpm and rapidly move the governor control shaft to the full FUEL ON position and read the measurement on the dial indicator.

e. Release the governor control shaft.

f. Turn stop (5) in (clockwise).

g. Repeat Steps d, e and f until the dial indicator reads 1.0 ± 0.15 mm (.01 in) more than dimension measured in Step d. This will be in the FUEL ON direction.

h. After the adjustment is correct, hold stop (5) in position and tighten nut (4).

j. Check the setting again to make sure it did not change after nut (4) was tightened.


Hold Retainer In Position

5. Hold retainer (8) in position and loosen nut (6). This keeps the fuel ratio control diaphragm from turning when nut (6) is loosened or tightened.

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


Adjustment Of Fuel Ratio Control

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

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

8. After the correct adjustment has been made, tighten nut (6). Check the dynamic fuel ratio control setting again.

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

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

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

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

12. Stop the engine.

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

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

15. Remove the rack position indicator tooling.

Check And Adjustment Of The Fuel Ratio Control Linkage For Use With Earlier Engines


6V6070 Governor Adjusting Tool Group

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

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


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

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


Indicator And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 6V6109 Bracket Assembly. (5) 2A0762 Bolt. (6) 8H9178 Ground Body Bolt. (7) 5P4814 Collet. (8) 6V6106 Dial Indicator.

2. Install the rack position indicator as follows:

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


Slot In Fuel Injection Pump Rack
(9) Slot.

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

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

d. Be sure the indicator arm moves freely.

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

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

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

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

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


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

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

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

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


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

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


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

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


Fuel Rack Against Timing Pin

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

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


6V7941 Compressor Assembly
(13) Rod.

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

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


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

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


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

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


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

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

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

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

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


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


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

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

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

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

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


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

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

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


Adjustment Of Fuel Ratio Control Linkage


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

Fuel Ratio Control And Governor Check (Later Engines)

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


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

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


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

2. Install the rack position indicator as follows:

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


Slot In Fuel Injection Pump Rack
(9) Slot.

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

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

d. Be sure the indicator arm moves freely.

e. Put dial indicator (8) of 8T1000 Electronic Position Indicator (10) in position in collet (7).

f. Put the 9S8903 Contact Point on the 6V2030 Extension and install on indicator (8) or (10).

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

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


Electronic Indicator And Centering Pin Installed
(3) 6V4186 Timing Pin. (4) 8T9198 Bracket Assembly. (5) 2A0762 Bolt. (6) 8H9178 Ground Body Bolt. (7) 5P4814 Collet. (10) 8T1000 Electronic Position Indicator.

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

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

5. Install 6V4186 Timing Pin (3) in rack zeroing hole near the front of the fuel injection pump housing.

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

7. Release the manual shutoff shaft and zero the dial or electronic indicator. If using the dial indicator, move the indicator assembly in the collet and tighten the collet when all three needles are on zero. If using the electronic indicator, press the zero button.

8. Remove 6V4186 Timing Pin (3) and note the change in indicator reading. The indicator should show movement in the FUEL ON direction. If no movement occurs, repeat Steps 5, 6 and 7 to zero the indicator.

9. Release the governor control shaft and linkage.


Remove Boost Line
(11) Air Line. (12) Fitting.

10. Remove air line (11) from engine. Put plugs over the openings to keep dirt out of the system.

------ WARNING! ------

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

--------WARNING!------

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

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

a. Connect a pressure gauge, a shutoff valve, a pressure regulator and an air supply to fitting (12).

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

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

d. If leakage is more than 20 kPa (3 psi) in 30 seconds, the fuel ratio control must be replaced before continuing to the next step.

e. Keep 70 kPa (10 psi) air pressure on the fuel ratio control for Step 13.

13. From low idle, rapidly move the governor control shaft to the full FUEL ON position and note the reading on the indicator. If using the dial indicator, read the indicator carefully because this reading will be a maximum for only a moment. The electronic indicator will hold and display the maximum reading. Make a record of the maximum indicator reading.

The maximum indicator reading is the dynamic full torque fuel setting of the engine. This setting is 0.5 mm (.02 in) greater than the static full torque setting given on the engine Information Plate of later engines or in the Fuel Setting And Related Information Fiche. If dynamic full torque setting is not reached, increase the air pressure to make sure there is full fuel ratio control movement. Do not exceed 100 kPa (15 psi).

14. Release all air pressure from the fuel ratio control. Start at 900 rpm and rapidly move the governor control shaft to the full FUEL ON position and note the reading on the indicator. If using the dial indicator, read the indicator carefully because this reading will be a maximum for only a moment. The electronic indicator will hold and display the maximum reading. Make a record of the maximum indicator reading. This is the dynamic fuel ratio control setting for the engine.

15. If the dynamic fuel ratio control setting is within ± 0.25 mm (.010 in) of the specification given on the Engine Information And Related Information Fiche, an adjustment is not necessary.

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

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

a. Connect a pressure gauge, a pressure regulator and an air supply to fitting (12).

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

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

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

e. Make a record of the first air pressure setting that gives full torque fuel setting. Full torque fuel setting was measured in Step 13.

f. This is the boost pressure that moves the fuel ratio control out of the rack control position. This pressure permits dynamic full torque fuel setting. If the pressure recorded in Step e is less than rated boost, the fuel ratio control cannot be a cause of low power complaint.

Fuel Ratio Control Adjustment (Later Engines)

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

1. See the Engine Information Plate or the Fuel Setting And Related Information Fiche for the correct dynamic fuel ratio control setting specification. Before an adjustment is made, record the difference between the correct specification and the dynamic fuel ratio control reading recorded in Step 14 of Fuel Ratio Control And Governor Check.

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


Fuel Ratio Control
(1) Clamp plate. (2) Bolt. (3) Air line. (4) Fuel ratio control. (5) Fitting.

------ WARNING! ------

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

--------WARNING!------

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

5. Loosen bolts (2) on clamp plate (1). The mating surfaces of clamp plate (1) and fuel ratio control (4) are serrated or "notched". A movement of one "notch" will change the dynamic fuel ratio control setting by 0.02 mm (.0008 in). Refer to the difference recorded in Step 1. Turn fuel ratio control (4) clockwise to get a more negative (less fuel) setting. Turn the control counterclockwise to get a more positive (more fuel) setting.

6. After an adjustment is made, tighten bolts (2) and recheck the dynamic fuel ratio control setting. Start at 900 rpm and rapidly move the governor control shaft to the full FUEL ON position and note the reading on the indicator. If using the dial indicator, read the indicator carefully because this reading will be a maximum for only a moment. The electronic indicator will hold and display the maximum reading. Make a record of the maximum indicator reading. Compare this reading to the correct dynamic fuel ratio control setting specification. Repeat the adjustment procedure as required until the correct setting is achieved.

7. Stop the engine.

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

9. Install air line (3) on the engine.

10. Remove the rack position indicator tooling.

Engine Speed Measurement


6V3121 Multitach Group

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

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

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

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

Governor Adjustments


NOTICE

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


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

Low Idle Adjustment

NOTE: The correct Low Idle rpm is given in the Fuel Setting And Related Information Fiche.

------ WARNING! ------

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

--------WARNING!------

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


Low Idle Adjustment
(1) Low idle stop screw.

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

Checking Set Point (Balance Point)

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

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

The 6V4060 Engine Set Point Indicator Group with the 6V2100 Multitach can be used to check the set point. Special Instruction Form No. SEHS7931 gives instructions for installation and use of this tool group.


6V4060 Engine Set Point Indicator Group

Alternate Method

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

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

A. At 20 rpm greater than full load speed.
B. The rpm where the fuel setting ajustment screw stop or first torque spring just make contact.

Use the procedure that follows to check the set point. Make reference to Techniques For Loading Engines in Special Instruction Form No. SEHS7050.

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


Terminal Location
(2) Brass terminal screw.

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

------ WARNING! ------

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

--------WARNING!------

3. Start the engine.

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

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

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

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

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

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

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

Adjusting Set Point (Balance Point)

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

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


Remove Cover
(3) Cover.


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

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

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

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

Dashpot Adjustment


Adjustment Of Dashpot
(1) Needle Valve.

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

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

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

2. Check governor operation.

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

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

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

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

Back pressure from the exhaust (pressure difference measurement between exhaust at outlet elbow and atmospheric air) must not be more than 1016 mm (40 in) of water.

Measurement Of Pressure In Inlet Manifold

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

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

a. 737 mm (29 in) of mercury (DRY) barometric pressure.
b. 29°C (85°F) outside air temperature.
c. 35 API rated fuel.

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


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

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


1U5470 Engine Pressure Group

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

Exhaust Temperature

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

Air To Air Aftercooled Systems

Visual Inspection

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

------ WARNING! ------

Pressure air can cause personal injury.

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

--------WARNING!------

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

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

Air System Restriction

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

Turbocharger Failure

------ WARNING! ------

Pressure air can cause personal injury.

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

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

--------WARNING!------

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


NOTICE

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


Inlet Manifold Pressure

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

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

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

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

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

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

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

Aftercooler Core Leakage


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

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


NOTICE

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


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

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


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

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

------ WARNING! ------

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

--------WARNING!------


Pressurize System
(5) Regulator and valve assembly.

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


NOTICE

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


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

5. Inspect all connections for air leakage.

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

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

------ WARNING! ------

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

--------WARNING!------

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

Dynamometer Test

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

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

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

Crankcase (Crankshaft Compartment) Pressure

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


8T2700 Indicator Group

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

Compression

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

Cylinder Head

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

Valves

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

Valve Seat Inserts

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

Valve Guides

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

Checking Valve Guide Bores

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

Bridge Dowel

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

Bridge Adjustment

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


Dimensions For Reconditioning Bridge Seat

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

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

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

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

NOTE: Valves must be fully closed.


Bridge Adjustment

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

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

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

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

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

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

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

Valve Clearance Setting

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

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


Valve Clearance Check

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

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

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


Valve Adjustment

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

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

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

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


Cylinder And Valve Location

Jake Brake Adjustment

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

Use the procedure that follows to make the adjustment:


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

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

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

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

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

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

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

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

Lubrication System

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

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

Too Much Oil Consumption

Oil Leakage On Outside Of Engine

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

Oil Leakage Into Combustion Area Of Cylinders

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

1. Oil leakage between worn valve guides and valve stems.
2. Worn or damaged piston rings, or dirty oil return holes
3. Compression ring and/or intermediate ring not installed correctly.
4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.

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

Measuring Engine Oil Pressure

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

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


1U5470 Engine Pressure Group

This tool group has a gauge to read oil pressure in the engine. Special Instruction, Form No. SEHS8907 is with the tool group and gives instructions for the test procedure.

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


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


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

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

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

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

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

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


Engine Oil Pressure Graph

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

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

Oil Pressure Is Low

Crankcase Oil Level

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

Oil Pump Does Not Work Correctly

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

Oil Filter Bypass Valves

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

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

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

Piston Cooling Tubes (Jets)

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

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

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

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

Oil Pressure Is High

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

Too Much Bearing Wear

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

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

Increased Oil Temperature

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

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

Cooling System

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

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

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

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

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

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

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

Testing The Cooling System

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

Test Tools For Cooling System


8T0470 Thermistor Thermometer Group

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


8T2700 Blowby/Air Flow Indicator Group

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


6V3121 Multitach Group

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


9S8140 Cooling System Pressurizing Pump Group

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

------ WARNING! ------

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

--------WARNING!------

Checking Pressure Cap

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

------ WARNING! ------

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

--------WARNING!------

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


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

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

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

------ WARNING! ------

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

--------WARNING!------

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

1. Remove the pressure cap from the radiator.

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

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

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

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

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

Testing Radiator And Cooling System For Leaks

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

------ WARNING! ------

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

--------WARNING!------

1. Remove the pressure cap from the radiator.

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

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

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

5. Check the radiator for outside leakage.

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

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

Gauge For Water Temperature


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

If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the gauge for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place can not be found where there is coolant leakage check the accuracy of the gauge for water temperature. A temperature gauge of known accuracy can be connected at the location for plugs (2) or (3) to make this check. Also, the 8T0470 Thermistor Thermometer Group or the 2F7112 Thermometer and 6B5072 Bushing can be used.

------ WARNING! ------

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

--------WARNING!------


Water Temperature Gauge

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

Water Temperature Regulators

1. Remove the regulator from the engine.

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

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

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

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

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

Belt Tension Chart

Basic Block

Piston Rings

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


Instructions For 1U6431 Gauge Group

Connecting Rods And Pistons

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

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

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

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

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

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

4. Tighten each nut 120° from the mark.

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

Connecting Rod And Main Bearings

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

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

Cylinder Block


1P3537 Dial Bore Gauge Group

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

Projection Of Cylinder Liner

Check liner projection above top plate as follows:

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


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


Rework old spacer plate to fabricate "figure 8" sections.

Make reference to Cylinder Liner Projection in Testing and Adjusting for the complete procedure.

NOTE: On engines with aluminum spacer plates, use care in obtaining liner projection measurements to prevent marring the surface. To prevent damage to the spacer plate, use copper washers instead of hardened steel washers with the spacer plate bolts. Do not excessively tighten the spacer plate bolts.

In addition, to increase the accuracy of liner projection measurements and also prevent damage, cut "figure 8" sections from an old spacer plate and install them under the spacer plate bolts. These are the center ribs between the cylinder holes from a scrapped 2W8601 Spacer Plate as shown in the illustration. The top and bottom radii of the "figure 8" section should coincide with the radii of the washers.

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

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

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

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

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

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

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


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

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

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

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

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

Flywheel And Flywheel Housing

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

Face Run Out (Axial Eccentricity) Of The Flywheel Housing

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


8T5096 Dial Indicator Group Installed


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

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

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

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

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

Bore Runout (Radial Eccentricity) Of The Flywheel Housing


8T5096 Dial Indicator Group Installed

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

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

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

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

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

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


Checking Bore Runout Of The Flywheel Housing

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

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

8. Add lines I and II by columns

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

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

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


Graph For Total Eccentricity

Face Runout (Axial Eccentricity) Of The Flywheel

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


Checking Face Runout Of The Flywheel

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

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

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

Bore Runout (Radial Eccentricity) Of The Flywheel

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


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

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

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

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

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

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


Checking Flywheel Clutch Pilot Bearing Bore

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

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

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

Vibration Damper

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

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


Vibration Damper
(1) Alignment marks.

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

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

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

3. Adjust the dial indicator to zero.

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

Electrical System

Test Tools For Electrical System

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

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


6V4930 Battery Load Tester

The 6V4930 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to load test all 6, 8 and 12 Volt batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals, and a load adjustment knob on the front panel permits a current range up to a maximum of 700 amperes. The tester also has a thermomoter to show when the safe operating temperature limit of the unit has been reached.

NOTE: Make reference to Special Instruction, Form No. SEHS8268 for more complete information for use of the 6V4930 Battery Load Tester.


8T0900 AC/DC Clamp-On Ammeter

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

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

NOTE: Make reference to Special Instruction, Form No. SEHS8420 for more complete information for use of the 8T0900 Clamp-On Ammeter.


6V7070 Heavy-Duty Digital Multimeter

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

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

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

Battery

------ WARNING! ------

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.

--------WARNING!------

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

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

Charging System

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

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

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

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

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

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

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

Alternator Regulator Adjustment (Delco-Remy)

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


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

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

Alternator Pulley Nut Tightening (Delco-Remy)

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


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

Starting System

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

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

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

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

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

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

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

Pinion Clearance Adjustment (Delco-Remy)

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


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

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

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

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

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


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

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

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

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

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

Pinion Clearance Adjustment (Bosch)

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


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

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

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

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

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