Fuel System

Either too much fuel or not enough fuel for combustion can be the cause of a problem in the fuel system.

Many times work is done on the fuel system when the problem is really with some other part of the engine. The source of the problem is difficult to find, especially when smoke comes from the exhaust. Smoke that comes from the exhaust can be caused by a defective fuel injection valve, but it can also be caused by one or more of the reasons that follow:

a. Not enough air for good combustion.

b. An overload at high altitude.

c. Oil leakage into combustion chamber.

d. Not enough compression.

e. Fuel injection timing retarded.

Fuel System Inspection

To check for low fuel pressure, remove the 1/8" Pipe Plug from the fuel filter base. Connect a pressure gauge from the 1U5470 Engine Pressure Group to the hole where the plug was removed. Run the engine at high idle and check the fuel pressure reading. The fuel pressure must be at least 158 kpa (23 psi).

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

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

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

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

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

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

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

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

Checking Engine Cylinders Separately

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

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

2. Orifice wear.

3. Steel wire brushing of nozzle tip.

Testing Fuel Injection Nozzles

NOTE: For more information on the 5P5140 Nozzle Testing Group see, Special Instruction, Form No. SEHS7292.

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

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

5P4150 Nozzle Testing Group
(1) 8N7005 Nozzle Assembly. (A) 5P7448 Adapter. (B) 5P4146 Gauge, 0 to 6900 kPa (0 to 1000 psi). (C) 6V2170 Tube Assembly. (D) 2P2324 Gauge, 0 to 34 500 kPa (0 to 5000 psi). (E) Gauge protector valve for 2P2324 Gauge. (F) FT1384 Extension. (G) Gauge protector valve for 5P4146 Gauge. (H) On-off valve. (J) 8S2270 Fuel Collector. (K) Pump isolator valve.

Extra Valve
(L) Gauge protector valve (must be in open position at all times).

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

Valve Opening Pressure Test.Flush the Nozzle.Tip Leakage Test.Orifice Restriction Test.Bleedscrew Leakage Test.

Nozzle Preparation for Test

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

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

Remove carbon dam (2) with needle nose pliers and remove seal (3) from the nozzle.

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

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

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

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

Fuel Injection Nozzle
(4) Bleed screw and seal.

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

NOTE: The bleed screw and seal must be removed for all tests except the Bleed Screw Leakage Test.

Valve Opening Pressure Test (VOP)

1. Install 6V2170 Tube Assembly (C) to the tester.

2. Install fuel injection nozzle with 5P7448 Adapter (A) on tube assembly (6). Position the bleed screw hole toward the tester and in line with 6V2170 Tube Assembly (C). This will make the fuel spray pattern horizontal. Be sure the nozzle tip is down and extends into FT1384 Extension (F) and 8S2270 Fuel Collector (J).

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

Nozzle Ready For Test
(E) Gauge protector valve. (H) On-off valve. (K) Pump isolator valve.

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

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

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

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

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

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

Flush the Nozzle

1. Close gauge protector valve (E). Close on-off valve (H). Open pump isolator valve (G).

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

2. Operate the pump rapidly for three full strokes.

Tip Leakage Test

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

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

Nozzle Ready For Test
(E) Gauge protector valve. (H) On-off valve. (K) Pump isolator valve.

3. Open gauge protector valve (E). Close on-off valve (H). Open pump isolator valve (K).

4. Make and hold for 15 seconds a pressure of 1380 to 2000 kPa (200 to 290 psi) less than the opening pressure measured in the VOP Test and make a note of the number of drops that fall.

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

Orifice Restriction Test

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

2. Point the tip of the fuel injection nozzle into the 8S2270 Fuel Collector and FT1384 Extension. Be sure the bleed screw hole is positioned toward the tester and is in line with 6V2170 Tube Assembly (C). This will make the fuel injection nozzle be 15° from vertical and the spray pattern will be horizontal.

3. Make a rapid increase in pressure and look at the orifice discharge (shape of discharge) when fluid begins to flow through the fuel injection nozzle. The discharge must be the same through all nine orifices. Any change either vertically or horizontally, is an indication of a defective nozzle.

Good Nozzle (Use Again)

Typical Discharge For Orifice With A Restriction (Replacement Necessary)

Typical Discharge With Horizontal Distortion (Replacement Necessary)

Typical Discharge With Vertical Distortion (Replacement Necessary)

Bleed Screw Leakage Test

Bleed Screws For Fuel Injection Nozzle

1. Install bleed screw (4) and the seal (washer) in the fuel injection nozzle. Tighten a type (A) bleed screw to 0.9 ± 0.1 N·m (8 ± 1 lb in). Tighten a type (B) or (C) bleed screw to 1.8 ± 0.2 N·m (16 ± 2 lb in). (Use the 6V4980 Torque Screw Driver to tighten the bleed screw to the correct torque.)

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

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

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

4. Pump the tester until fuel injection nozzle is full of fluid and the pressure on the gauge is 12 800 to 14 800 kPa (1870 to 2165 psi).

NOTE: 15 or 20 strokes of the pump can be necessary for the pressure to get to 12 800 to 14 800 kPa (1870 to 2165 psi).

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

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

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

Fuel Injection Lines

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

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

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

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

Checking The Plunger And Lifter Of An Injection Pump

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

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

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

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

Removal of Fuel Injection Pumps

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

NOTE: The fuel rack must be in the center position before the fuel injection pumps can be removed.

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

Fuel Injection Pump Housing
(1) Timing pin cover.

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

Timing Pin Installed
(2) Timing pin.

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

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

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

6. Install the 8S2244 Extractor on the threads of the injection pump. Carefully pull the pump straight up out of the bore.

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

Installation of Fuel Injection Pumps

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

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

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

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

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

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

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

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

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

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

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

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

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

b. Set the governor at low idle.

Stopping The Engine (Typical Example)

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

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

Locating Top Center Compression Position For No.1 Piston

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

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

1. Remove starting motor.

2. Install the tools as shown.

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

3. Remove the valve cover.

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

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

Valve Cover Removed
(4) Rocker arms.

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

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

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

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

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

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

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

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

When checking the dynamic timing on an engine without a mechanical advance, Caterpillar recommends that the 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.

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

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

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

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 a torque of not more than 40 N·m (30 lb ft).

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

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

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

8. Connect the cables from the transducer to Engine Timing Indicator (1). Calibrate and make adjustments. For calibration procedure, make reference to Special Instruction, 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 100 rpm speed increments between 1000 rpm (base rpm) and high idle. (Smaller increments may be needed to find the point where timing advance starts and stops). Record and plot the engine timing indicator readings over the calculated timing graph.

11. If the reading are within ± 2.5° of the calculated timing graph and the angle of change is approximately the same, the engine timing is set and operating correctly.

12. If the timing indicator reading are not within ± 2.5° of the calculated graph and timing advance is not smooth through the speed range, an adjustment may be needed.

13. Make reference to Checking Engine Timing By Timing Pin Method for static adjustment of the fuel injection pump drive. Check engine timing again if the static engine timing was not correct. If the automatic timing advance is not correct, make a repair or replacement of the automatic advance unit. There is no adjustment to the unit.

Checking Engine Timing By Timing Pin Method

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

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

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

Timing Pin Installed
(4) 6V4186 Timing Pin.

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

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

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

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

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

Timing Gear For Fuel Injection Pump
(5) Bolt.

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

8. Install 8S2264 Puller Group and loosen the timing gear from the fuel pump camshaft.

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

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

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

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

12. Install 4C9874 Spanner Wrench on the timing gear.

Adapter Installed On Timing Gear
(10) 4C9874 Spanner Wrench.

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

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

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

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

Governor Adjustment For Fuel Ratio Control Linkage

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

Fuel Injection Pump And Governor
(1) Cover.

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

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

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

Cover Removed
(4) Slot on fuel rack.

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

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

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

Dial Indicator Installed
(7) 6V3075 Dial Indicator.

4. Put 9S229 Contact Point, 9.7 mm (.38 in) long on 6V3075 Dial Indicator (7) and install dial indicator in collet (2).

Governor
(8) Fuel ratio control

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

Rear Of Governor Housing
(9) Plug.

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

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

Timing Pin Installed
(10) 6V4186 Timing Pin.

8. Install 6V4186 Timing Pin (10) in the hole in the bracket assembly. Push timing pin in until contact is made with the fuel rack. Hold the timing pin gently against the fuel rack for Steps 9 and 10. If too much force is used to hold the timing pin, the fuel rack can stick and cause an incorrect zero reading.

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

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

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

10. Insert 6V7942 Hook (11) into the hole that plug (9) was removed from. Engage the end of hook (11) with collar (12) and pull toward the rear of the governor housing until the collar stops moving. This will make sure the fuel rack stops against the timing pin. This is the rack zero position.

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

12. Remove timing pin (10).

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

Compressor Assembly Installed
(15) 6V7941 Compressor Assembly.

13. Turn rod (13) out of 6V7941 Compressor Assembly (15) until knob (14) is 25.4 mm (1.0 in) from the compressor body. Install 6V7941 Compressor Assembly (15) in the hole plug (9) was removed from.

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

14. Move the governor control lever to the FUEL OFF position. Use two S1614 Bolts and install 6V2017 Governor Adjustment Tool (16). Be sure the end of the tool is behind the governor linkage, and that the flange is completely against the governor housing (the filter screen may have to be removed).

NOTE: If it is expected to be necessary to change the setting, install the outer part of 6V2106 Rack Adjusting Tool (17) along the left side of the 6V2017 Adjusting Tool when the 6V2017 Adjusting Tool is installed.

15. Move the governor control to the FULL LOAD position and hold in this position.

16. Turn the spring assembly rod IN (clockwise) until the indicator hand stops moving. This is the STATIC FUEL RATIO CONTROL LEVER SETTING.

17. Slowly turn the rod OUT (counterclockwise) until the indicator hand stops moving. This is the STATIC FUEL RATIO CONTROL LEVER SETTING.

NOTE: There will be a small initial movement of the dial indicator hands, then, they will stop moving while the rod is turned out for another 11/2 turns. Now the indicator hands will begin to move again and will follow the turning of the rod until the setting is reached. It is important that the rod be turned slowly so that the rack can follow the governor components.

18. Make reference to the Fuel Setting And Related Information Fiche for the correct fuel ratio lever setting and compare to the dial indicator reading.

Governor Linkage Adjustment
(17) 6V2106 Rack Adjustment Tool Group.

19. If the fuel ratio control setting is not correct, use 6V2106 Rack Adjustment Tool (17) to loosen the locknut and turn the adjustment screw (18). Turn the screw clockwise to decrease the amount of fuel possible (less rack travel) at the limited rack position.

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

Adjustment Screw For Governor
(18) Adjustment screw.

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

Fuel Ratio Control And Governor Check

NOTE: The governor seals do not have to be cut or removed for the checking procedures that follow. For more information on the tooling and procedures, see Video Tape Form No. SEVV9173 and Special Instruction Form No. SEHS8463 available on microfiche only.

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

2. Turn the engine start key ON 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 in the pump housing.

5. With the governor control lever in the full FUEL OFF 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 collet 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 Air Line

9. Remove the air line from the engine. Put plugs over the opening to keep dirt out of the system.

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

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

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

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 the fitting from which the air line was removed.

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

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

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

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

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

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 the 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 of later engines or in the Fuel Setting And Related Information Fiche.

NOTE: On engines with the fuel ratio control 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 this dial indicator reading. This is the dynamic fuel ratio control setting for the engine.

14. If the dynamic fuel ratio setting is within ± 0.25 mm of the specifications on the Engine Information Plate or 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 follows:

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

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

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

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 and adjustment is made.

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

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

Earlier Fuel Ratio Control
(1) Nut. (2) Retainer. (3) Stop. (4) Nut. (5) Extension.

NOTE: On earlier engines, Step 4 must be done to make sure that stop (3) does not contact retainer (2). Later engines do not have stop (3) and nut (4). Do not add these parts when the fuel ratio control is repaired.

4. Loosen nut (4) and turn stop (3) in (clockwise) until the stop makes contact with the shoulder on retainer (2). Now turn the stop out (counterclockwise) two completed turns and tighten nut (4).

Later Fuel Ratio Control
(1) Nut. (5) Extension.

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

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

6. Activate the fuel ratio control by pushing in on valve extension (5).

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

8. Turn valve extension (5) to get the correct setting. A clockwise direction will give a more positive setting. The counterclockwise direction will give a more negative setting. Several adjustments of valve extension (5) may be needed to get the correct dynamic fuel ratio control setting.

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 (1). Check the dynamic fuel ratio control setting again.

11. Install the gasket and cover 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 the fitting. 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 the air line on the engine.

17. Remove the rack position indicator tooling.

Fuel Setting Procedure

The static fuel setting can be done with the fuel injection pump and governor on or off the engine. For more information on the fuel setting procedure, see Special Instruction, Form No. SEHS8024.

Fuel Injection Pump And Governor
(1) Cover.

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

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

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

Cover Removed
(4) Slot on fuel rack.

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

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

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

Dial Indicator Installed
(7) 6V3075 Dial Indicator.

4. Put 9S229 Contact Point, 9.7 mm (.38 in) long on 6V3075 Dial Indicator (7) and install dial indicator in collet (2).

Governor
(8) Fuel ratio control

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

Rear Of Governor Housing
(9) Plug.

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

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

Timing Pin Installed
(10) 6V4186 Timing Pin.

8. Install 6V4186 Timing Pin (10) in the hole in the bracket assembly. Push timing pin in until contact is made with the fuel rack. Hold the timing pin gently against the fuel rack for Steps 9 and 10. If too much force is used to hold the timing pin, the fuel rack can stick and cause an incorrect zero reading.

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

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

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

10. Insert 6V7942 Hook (11) into the hole that plug (9) was removed from. Engage the end of hook (11) with collar (12) and pull toward the rear of the governor housing until the collar stops moving. This will make sure the fuel rack stops against the timing pin. This is the rack zero position.

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

12. Remove timing pin (10).

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

Compressor Assembly Installed
(15) 6V7941 Compressor Assembly.

13. Turn rod (13) out of 6V7941 Compressor Assembly (15) until knob (14) is 25.4 mm (1.0 in) from the compressor body. Install 6V7941 Compressor Assembly (15) in the hole plug (9) was removed from.

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

Checking Static Fuel Setting
(16) 8T0500 Circuit Tester. (17) Rack contact screw. (18) Adjustment screw cover.

14. Fasten the clip end of 8T0500 Circuit Tester (16) to rack contact screw (17) and put the other end to a good electrical ground.

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

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

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

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

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

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

Adjustment Screw Cover Removed
(19) Fuel setting screw.

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

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 11/8 turns. Recheck the new setting and readjust if necessary.

Negative numbers work differently than positive numbers. If one number (-1.25) has a larger digital value than another one (-1.05), the first number (-1.25) is actually less than the other one. Therefore, in this example the "desired setting" is lower than the "actual reading." Turn the 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 11/8 turns. Recheck the new setting and readjust if necessary.

The "desired setting" is lower than the "actual reading." Turn the adjusting screw in approximately 27/8 turns.

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

Adjusting Fuel Setting
(20) 6V2106 Rack Adjustment Tool Group.

20. Use 6V2106 Rack Adjustment Tool Group (20) to loosen the locknut for adjustment screw and to turn the adjustment screw.

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

Engine Speed Measurement

6V3121 Multitach Group
(1) Carrying case. (2) Power cable. (3) Tachometer generator. (4) Tachometer drive group. (5) Multitach.

The 6V3121 Multitach Group can measure engine speed from a tachometer drive on the engine. It also has the ability to measure engine speed from visual engine parts in rotation.

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.

6V4950 Injection Line Speed Pickup Group
(6) 6V6114 Pickup. (7) 6V6113 Amplifier.

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

Governor Adjustments

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NOTICE
A 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 Measuring Engine Speed.

Low Idle Adjustment

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

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

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

Low Idle Adjustment
(1) Cover. (2) Low idle screw.

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

Checking Set Point (Balance Point)

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

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

The 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

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

A. At 20 rpm greater than full load speed.

B. The rpm where the fuel setting adjustment screw and stop or first torque spring just make contact.

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

Terminal Location
(3) Brass terminal screw.

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

2. Connect the clip end of the 8T0500 Circuit Tester to the brass terminal screw (3) on the governor housing. Connect the other end of the tester to a place on the fuel system which is a good ground connection.

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

3. Start the engine.

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

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

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

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

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

9. Stop the engine. Make a comparison of the records from Steps 5 and 7 with the information from the Engine Information Plate. If the Engine Information Plate is not available, see the Fuel Setting And Related Information Fiche.

The tolerance for the set point is ± 10 rpm. The tolerance for the high idle rpm is ± 30 rpm. If the readings from Steps 5 and 7 are within the tolerance, no adjustment is needed.

NOTE: It is possible in some applications that the high idle rpm will be less than the lower limit. This can be caused by high parasitic loads such as hydraulic pumps, compressors, etc.

Adjusting Set Point (Balance Point)

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

2. If the set point rpm is not correct, remove cover (1) and loosen locknut. Turn adjustment screw (4) to adjust the set point to the midpoint of the tolerance.

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

Set Point Adjustment
(4) Adjustment screw.

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

Dashpot Screw Adjustment

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

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

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

Dashpot Screw Adjustment
(1) Dashpot adjustment screw.

Air Inlet And Exhaust System

Restriction Of Air Inlet And Exhaust

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

Air flow through the air cleaner must not have a restriction of more than 762 mm (30 in) of water difference in pressure.

Back pressure from the exhaust (pressure difference measurement between exhaust outlet elbow and atmosphere) must not be more than 1016 mm (40 in) H₂O on engines with a turbocharger.

Measurement Of Pressure In Inlet Manifold

By checking the pressure in the inlet manifold the efficiency of an engine can be checked by making a comparison 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: 746.7 mm (29.4 in) of mercury barometric pressure, 29°C (85°F) outside air temperature and 35 API rated fuel. Any change from these conditions can change the pressure in the inlet manifold. Outside air that has higher temperature and lower barometric pressure than given above will cause a lower horsepower and inlet manifold pressure measurement, than given in the Fuel Setting And Related Information Fiche. Outside air that has a lower temperature and higher barometric pressure will cause a higher horsepower and inlet manifold pressure measurement.

A difference in fuel rating will also change horsepower and the pressure in the inlet manifold. If the fuel is rated above 35 API, pressure in the inlet manifold can be less than given in the 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.

NOTE: Be sure that the air inlet and exhaust do not have a restriction when making a check of pressure in the inlet manifold.

1U5470 Engine Pressure Group

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

This tool group has a gauge to read pressure in the inlet manifold. Special Instruction, Form No. SEHS8524 is with the tool group and gives information on the use of the group.

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

Air To Air Aftercooler 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.

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

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

The use of winter fronts or shutters is discouraged with air to air aftercooled systems. 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

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

If a turbocharger failure occurs, remove the air to air 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.

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

Inlet Manifold Pressure

Normal inlet manifold pressure with high exhaust temperature can be caused by 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 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.

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

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

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

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.

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

Pressurize System
(5) Regulator and valve assembly.

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

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

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

5. Inspect all connections for air leakage.

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

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

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

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

Exhaust Temperature

6V5000 Infrared Thermometer Group

Use the 6V5000 Infrared Thermometer Group to check exhaust temperature. Special Instruction, Form No. SEHS8149 is with the tool group and gives instructions for the test procedure.

Turbocharger

Every 4800 hours or if any unusual sound or vibration in the turbocharger is noticed, a quick check of bearing condition can be made without disassembling the turbocharger. This can be done by removing the piping from the turbocharger and inspecting the compressor impeller, turbine wheel and compressor cover. Rotate the compressor and turbine wheel assembly by hand and observe by feeling excess end play and radial clearance. The rotating assembly should rotate freely with no rubbing or binding. If there is any indication of the impeller rubbing the compressor cover or the turbine wheel rubbing the turbine housing, recondition the turbocharger or replace with a new or rebuilt one.

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

Refer to the Specifications for the correct end play dimensions. If end play is more than the maximum end play, rebuild or replace the turbocharger. End play less than the minimum end play could indicate carbon buildup on the turbine wheel and should be disassembled for cleaning and inspection.

Checking Turbocharger Rotating Assembly End Play (Typical Example)

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

Crankcase (Crankshaft Compartment) Pressure

Pistons or piston rings that have damage can be the cause of too much pressure in the crankcase. This condition 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

Normal crankcase pressure with a clean crankcase breather is 50.8 mm (2 in) of water or less.

Compression

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

Cylinder Head

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

Valves

Valve removal and installation is easier with use of the 5P1330 Valve Spring Compressor Assembly and 5S1322 Valve Keeper Inserter.

Valve Seat Inserts

Tools needed to remove valve seat inserts are in the 6V4805 Valve Insert Puller Group. Refer to the Disassembly And Assembly section of this manual for an explanation for this procedure. The insert can be more easily installed by lowering the temperature of the insert before installing it in the head.

Valve Guides

Tools needed to install valve guides are: 7S8858 Driver Bushing and 7S8859 Driver. The counterbore in the driver bushing installs the guide to the correct height. Use a 1P7450 Honing Arrangement to make a finished bore in the valve guide after installing the guide in the head. Refer to the Disassembly And Assembly section of this manual for an explanation for this procedure.

Checking Valve Guide Bore

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.

5P3536 Valve Guide Gauge Group

Valve Lash

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

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

Valve Lash

Cylinder And Valve Identification

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

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

3. Turn the flywheel 360° in the direction of engine rotation. This will put No. 6 piston at top center (TC) on the compression stroke.

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

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

Compression Brake Slave Piston Adjustment

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NOTICE
The following adjusting procedure must be strictly adhered to. Any other method of adjusting the slave piston clearance is not authorized and may result in serious engine and/or engine brake damage.

Slave piston adjustment must be made with the engine stopped and cold. The exhaust valves on the cylinder to be adjusted must be in the closed position.

Use the procedure that follows to make the adjustment:

(1) Slave piston adjustment screw. (2) Locknut.

Use the procedure that follows to make the adjustment:

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. Make adjustments to cylinders 1, 3, and 5.

(3) Jacobs Lash Adjusting Gauge. (4) Wrench.

2. Loosen locknut (2). With the exhaust valves closed (rocker arms loose) turn in the slave piston adjustment screw until the slave piston contacts the valve stem cap.

3. Place the Jacobs Lash Adjusting Gauge (3) over slave piston adjustment screw (1) and locknut (2) so that the "A" mark is in line with the wrench (4).

4. Hold the Jacobs Lash Adjusting Gauge (3) in position and turn wrench (4) in the counterclockwise direction from the "A" mark to the "B" mark on the gauge. This will provide a slave piston clearance of 0.89 mm (0.035 in). Tighten locknut (2) to a torque of 35 N·m (25 lb ft). Repeat procedure for cylinders 3 and 5.

5. 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.

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

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

Too Much Oil Consumption

Oil Leakage on Outside of Engine

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

Oil Leakage Into Combustion Area Of Cylinders

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

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

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

3. Compression ring 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. SEHS8524 is with the tool group and gives instructions for the test procedure.

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

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

Oil Pressure Switch Location
(1) Oil pressure switch.

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

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

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

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

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

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

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

Oil Filter Bypass Valve

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

Too Much Clearance at Engine Bearings or Open Lubrication System (Broken or Disconnected Oil Line or Passage)

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

Piston Cooling Tubes (Jets)

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

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

Oil Pressure Is High

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

Too Much Bearing Wear

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

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

Increased Oil Temperature

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

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

Cooling System

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

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

Visual Inspection Of The Cooling System

1. Check coolant level in the cooling system.

2. Look for leaks in the system.

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

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

4. Inspect the drive belts for the fan.

5. Check for damage to the fan blades.

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

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

Testing The Cooling System

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

Boiling Point Of Water

Test Tools for Cooling System

The 4C6500 Digital Thermometer Group is used in the diagnosis of overheating (engine hotter than normal) or overcooling (engine cooler than normal) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Operating Manual, Form No. NEHS0554.

4C6500 Digital Thermometer Group

The 8T2700 Blowby/Air Flow Indicator Group is used to check the air flow through the radiator core. The operating instructions are included with the group.

8T2700 Blowby/Air Flow Indicator Group

The 6V3121 Multitach Group is used to check the fan speed. The testing procedure is in Special Instruction, Form No. SEHS7807.

6V3121 Multitach Group

Checking Pressure Cap

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

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

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

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

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

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

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

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

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

9S8140 Cooling System Pressurizing Pump Group
(A) Release Valve. (B) Adapter. (C) Hose.

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

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

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

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

Testing Radiator and Cooling System for Leaks

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

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

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

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

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

4. Get the pressure reading on the gauge to 20 kPa (3 psi) more than the pressure on the pressure cap.

5. Check the radiator for outside leakage.

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

7. If you do not see any outside leakage and the pressure reading on the gauge is still the same after five 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.

Water Temperature Regulator

1. Remove the regulator from the engine.

2. Heat water in a pan. Check Specifications section for the correct temperature to use. 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 9.53 mm (.375 in), make a replacement of the regulator.

Basic Block

Connecting Rods And Pistons

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

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

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

1. Put 2P2506 Thread Lubricant on threads.

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

3. Put a mark on each nut and cap.

4. Tighten each nut 90° from the mark.

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

Connecting Rod And Main Bearings

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

Cylinder Liner Projection

The correct cylinder liner projection is important to prevent a leak between the liner, cylinder head, and block. Check cylinder liner projection above the spacer plate as follows:

1. Be sure that the surfaces of the cylinder block, cylinder liner, and the spacer plate are clean.

2. Install the spacer plate gasket and spacer plate (4) on the cylinder block. Use S1589 Bolts (1) with two 1S379 Washers on each bolt to hold the spacer plate to the cylinder block. Put two bolts with washers on each side of the opening for the cylinder liner. Tighten the bolts evenly. See the Specifications section in this manual for the proper procedure.

NOTE: To keep from moving bolts and washers as each liner is checked install two bolts with washers on each side of each cylinder liner, along the complete length of the spacer plate.

3. Install the cylinder liner without seals in the cylinder block. Put adapter plate (7) on the cylinder liner as shown. Install crossbar (2) with 1D4595 Bolts (3), 2S736 Washers and 3H0465 Plates (5) as shown. See the Specification section in this manual for the proper procedure. The measurement from the bottom of crossbar (2) to the spacer plate, must be the same on both sides of the cylinder liner.

4. Install the 1P5512 Contact Point on dial indicator (6). Put the dial indicator in the 1P2402 Gauge Body. To adjust the dial indicator to zero, put dial indicator and gauge body on the 1P5507 Gauge. Move the dial indicator until the hand moves 1/4 turn. Tighten bolt on body to hold the dial indicator in this position. Turn the dial face until the zero is in alignment with the hand.

Measuring Cylinder Liner Projection
(1) S1589 Bolt with two 1S379 Washers. (2) Crossbar. (3) 1D4595 Bolt. (4) Spacer plate. (5) 3H0465 Plates. (6) 1P2403 Dial Indicator. (7) 1P2394 Adapter Plate.

5. Measure the cylinder liner projection as close as possible to the four corners of the adapter plate on the liner. The liner projection must be 0.033 to 0.175 mm (.0012 to .0069 in). The difference between the four measurements must not be more than 0.05 mm (.002 in). The difference in the average cylinder liner projection of liners next to each other must not be more than 0.05 mm (.002 in). The maximum difference in the average projection for all cylinder liners must not be more than 0.10 mm (.004 in).

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

6. When the cylinder liner projection is correct, put a temporary mark on the liner and the spacer plate so at final installation the liner can be installed in the correct position.

Cylinder liner projection can be adjusted by the removal of material from (machining) the contact face of the cylinder block with the use of 8S3140 Cylinder Block Counterboring Tool Arrangement. The instructions for the use of the tool group are in Special Instruction, Form No. FM055228.

Cylinder Block

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

1P3537 Dial Bore Gauge Group

Flywheel And Flywheel Housing

Installing Ring Gear

Heat the ring gear to install it. Do not heat to more than 320°C (608°F). Install the ring gear so the chamfer on the gear teeth are next to the starting motor pinion when the flywheel is installed.

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.

The 4C4911 Battery Load Tester is a portable unit in a metal case for use under field conditions and high temperatures. It can be used to load test all 6, 8 and 12V batteries. This tester has two heavy-duty load cables that can easily be fastened to the battery terminals. A load adjustment knob on the top permits the current being drawn from the battery to be adjusted to a maximum of 100 amperes. The tester is cooled by an internal fan that is automatically activated when a load is applied.

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

NOTE: Make reference to Operating Manual, Form No. SEHS9249 for more complete information for use of the 4C4911 Battery Load Tester.

8T0900 AC/DC Clamp-On Ammeter

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

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

NOTE: Make reference to Special Instruction, Form No. SEHS8420 for more 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 checking 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

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

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

Use the 4C4911 Battery Load Tester, the 8T900 Clamp-On Ammeter and the 6V7070 Multimeter to load test a battery that does not hold a charge when in use. See Special Instruction, Form No. SEHS8268 for the correct procedure and specifications to use.

Charging System

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

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

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

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

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

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

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

9L5938 Alternator; Pulley Nut Tightening

Tighten nut that holds the pulley to a torque of 100 ± 7 N·m (75 ± 5 lb ft) with the tools shown.

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

Starting System

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

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

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

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

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

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

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

Starting Motor Adjustments (3T2764) (8C3595)

Pinion Clearance Adjustment

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

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

1. Install the solenoid without connector (1) from the MOTOR connections (terminal) on solenoid to the motor.

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).

Starting Motor Adjustments (3T2371)

Solenoid Position Adjustment

Solenoid Assembly
(1) Intermediate housing. (2) Solenoid mounting bracket. (3) Bolts. (X) 62.5 + 0.2 -0.5 mm (2.46 + .008 -.020 in)

The solenoid position on the starting motor controls the pinion clearance. If the solenoid position dimension is correct, the pinion clearance is correct. The adjustment can be made with the starting motor removed.

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

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) after the adjustment is correct, to a torque of 7 to 10 N·m (5 to 7 lb ft).

Armature End Plate Adjustment

The armature end plate adjustment is made during assembly of the starting motor.

Starting Motor End Cover
(1) Plug. (2) Spacer. (X) Distance between armature and face of end cover. (Y) Length of plug threads.

1. Remove center plug (1) and spacer (2) from the end cover.

2. Force the armature assembly into the drive housing up against the spacer.

3. Measure distance (X) from the end cover to the armature assembly.

4. Measure length of threads (Y) of plug (1).

5. Subtract measurement (Y) from measurement (X). This difference is the armature end play. The allowable end play is 0.1 to 0.4 mm (.004 to .012 in). The end play can be adjusted with different spacers (2). The thickness of each is as follows:

1.5 mm (.059 in)1.7 mm (.067 in)1.9 mm (.075 in)2.1 mm (.083 in)2.3 mm (.090 in)2.5 mm (.100 in)

6. Install correct spacer (2). Put 9S3263 Thread Lock on threads of plug (1) and install it into the end cover.