There are two operation checks that are fast and need no special equipment. One check is the PULL-DOWN RPM CHECK to see if the BrakeSaver can give full braking force. The other check is the KLUNK CHECK to see if the valve spool in the BrakeSaver control valve has free movement. These two checks give an approximate indication that the BrakeSaver has the correct operation.
Pull-Down RPM Check
NOTE: The engine must give rated horsepower for this test to have accuracy.
1. Actuate the brakes, put the transmission in NEUTRAL and operate the engine at high idle rpm (accelerator pedal all the way down).
2. Make a record of the engine rpm.
3. Put the BrakeSaver control to the full ON position.
4. Make a record of the engine rpm with the BrakeSaver full on.
5. The engine rpm with the BrakeSaver full on must be 175 ± 25 rpm less than the engine rpm with the BrakeSaver off.
NOTE: If the difference in rpm is less than 150 rpm, the BrakeSaver is not giving full braking force.
NOTE: If the difference in rpm is more than 200 rpm, check the air pressure to the BrakeSaver control valve. The air pressure must not be more than 42 psi (290 kPa).
Do not run the engine at high idle rpm with the BrakeSaver ON for more than 15 seconds at a time. Let the engine run at low idle with the BrakeSaver off for five minutes to keep from getting the engine cooling system too hot.
Klunk Check (check for free movement of the valve spool)
1. Run the engine until the truck air system is at its maximum pressure and then stop the engine.
2. Put the BrakeSaver in the full ON position before the air pressure in the truck air system gets below 70 psi (480 kPa).
3. Put the BrakeSaver in the OFF position. A noise ("klunk") must be heard at the BrakeSaver control valve as the valve spool hits the cover at the air inlet end of the control valve.
4. If the noise is not heard at the BrakeSaver control valve, remove and disassemble the control valve. Inspect the valve for:
a. A damaged valve body.
b. Damaged or worn springs in the valve spool.
c. Damaged or worn valve spool.
d. Damaged or worn O-ring seals or diaphragm in the control valve.
e. Closed holes (small holes to feel pressure) in the side of the valve spool.
For specific problems, make reference to the PROBLEM INDEX below.
1. Air pressure to control valve. 2. Oil pressure to engine. 3. Oil pressure from oil cooler. 4. Oil pressure to BrakeSaver. 5. Oil pressure from BrakeSaver. 6. Oil pressure from engine. 7. Oil pressure to oil cooler.
Difficulty within the fuel system can be classed in one of two groups: lack of fuel or too much fuel for proper combustion.
Many times, the fuel system is blamed when the fault lies elsewhere, especially when smoky exhaust is the problem. Smoky exhaust can be the result of a faulty fuel injection valve, but it can also be caused by lack of air for complete combustion, overloading at high altitude, excessive oil burning or lack of compression.
1. Observe the fuel pressure gauge reading. Lack of pressure indicates difficulty in the supply side of the system.
2. Check the fuel level in the supply tank and the fuel tank cap vent for being plugged.
3. See that the vent valve is closed.
4. Check for leakage in the fuel supply lines and components or for a kinked or restricted supply line.
5. Replace the fuel filter element and clean the primary fuel filter.
6. Inspect the fuel bypass valve to see that it moves freely and that dirt is not holding the plunger off its seat. Be certain the spring has proper tension.
7. Bleed the fuel system to remove trapped air.
Testing Fuel Injection Equipment
A simple check can be made to determine which cylinder is misfiring or causes puffing black smoke. With the engine running at a speed which makes the defect most pronounced, momentarily loosen the fuel line nut on an injection pump sufficiently to "cut out" the cylinder. Check each cylinder in the same manner. If one is found where loosening makes no difference in the irregular operation or causes puffing black smoke to cease, the pump and valve for only that cylinder need be tested. Incomplete combustion in this particular cylinder can also be caused by low or no compression (worn or broken rings, leaking or incorrectly adjusted valves) so further testing may be necessary.
Checking Fuel Injection Valve
Examine fuel injection valves for:
- 1. Excessive carbon on tip of nozzle or in orifice.
- 2. Erosion of the orifice.
- 3. Screen plugged with dirt.
- 2. Erosion of the orifice.
The condition of a capsule-type nozzle assembly can be tested on the Caterpillar Diesel Fuel Injection Test Apparatus, and the rate of leakage of the nozzle assembly can be determined.
Checking Fuel Injection Pump Lifter Washer and Pump Plunger
The timing dimension should be checked and adjusted, if necessary, by setting the fuel injection pump timing dimension with the fuel injection pump off the engine. This will assure that the point of the fuel injection is correct. If the timing dimension is too small, injection will begin early, and if too great, injection will be late.
When pump plunger wear becomes excessive, the lifter washer may also be worn so it will not make full contact with the end of a new plunger. To avoid rapid wear on the end of the new plunger, replace the lifters having washers showing visible wear.
WEAR BETWEEN LIFTER WASHER AND PLUNGER
Fig. A illustrates the contact surfaces of a new pump plunger and a new lifter washer. In Fig. B the pump plunger and lifter washer have worn considerably. Fig. C shows how the flat end of a new plunger makes poor contact with a worn lifter washer, resulting in rapid wear to both parts.
A pump can maintain a satisfactory discharge rate and yet be unserviceable because of delayed timing resulting from wear on the lower end of the plunger. When testing a pump which has been in use for a long time, check the plunger length with a micrometer. Discard the pump if the plunger measures less than the minimum length (worn) dimension.
Inspect the upper diameter of the plunger for wear. Performance of pumps worn in this manner can be checked as described in the Instructions for Fuel Injection Test Apparatus.
Glow Plug And Precombustion Chamber Removal And Installation
Use 6H3425 Glow Plug Tool Group to remove and install glow plugs. Before installing a glow plug, put 9M3710 Anti-Seize Compound on threads of the glow plug. Tighten the glow plug to 120 ± 24 lb. in. (13.6 ± 2.8 N·m).
Use a 8F8353 Precombustion Chamber Wrench to remove and install precombustion chambers.
Before installing a precombustion chamber, put liquid soap in the bore and on the O-ring seal. Put 9M3710 Anti-Seize Compound on threads of the precombustion chamber. Tighten the precombustion chamber to 150 ± 10 lb. ft. (205 ± 14 N·m).
Fuel Injection Service
Fuel Injection Valve
Always inspect the seats of both the nozzle and the precombustion chamber prior to installing a fuel injection valve. The nozzle assembly should be finger tight on the body. It is important to maintain the nozzle retaining nut torque to 105 ± 5 lb. ft. (142 ± 7 N·m). Excessive torque will damage the nozzle. Less torque can cause the nozzle case to bulge or split and will allow the nozzle to leak resulting in fuel dilution of the crankcase oil. Any loose fuel line connections inside the camshaft housing can cause crankcase dilution and result in low oil pressure, bearing wear, and engine damage.
Fuel Injection Pump
When removing fuel injection pumps, spacers and lifters the components should be kept together and marked so they can be installed in their respective locations.
While disassembling fuel injection pumps, exercise considerable care to prevent damage to the plunger surfaces. The barrel and the plunger are matched and are not interchangeable. Use extreme care when inserting the plunger into the bore of the barrel.
Removing and Installing Fuel Injection Pump Assemblies
Total rack travel, approximately .800 in. (20.32 mm), will be reduced if the pump is installed one or more teeth off in either the "fuel on" or "fuel off" side of its gear segment. The only way to check for correct installation of pumps with engine stopped is to measure full rack travel with the entire governor removed, including piston and valve mechanism. Use the 9S240 Rack Positioning Tool Group and a 9S215 Dial Indicator to check rack travel.
The installation of fuel injection pump assemblies requires that the lifter be at a low point and the fuel rack be at the centered position. To install a fuel injection pump, proceed as follows.
1. Remove the air-fuel ratio control and depress the speed limiter.
2. Depress rack centering pin and move governor control lever in the fuel ON direction. The rack centering pin will drop into a slot in the fuel rack and stop rack movement when the rack is in the centered position. Secure the rack linkage in this position.
NOTE: Put the centering pin cover (1) partially over the centering pin (2) and tighten the bolt finger tight to hold down the centering pin.
3. Align the notches (4) on the bonnet and barrel with the slot (5) of the pump gear segment.
RACK CENTERING PIN LOCATION
1. Cover. 2. Pin.
4. Put the injection pump into the housing. Slot (5) must align with the dowel in the lifter and the notches in the bonnet and barrel must align with the dowels in the pump bore. Keep a downward force on the pump and install the retaining bushing.
ALIGNING NOTCHES WITH SLOT
3. 8S2244 Extractor. 4. Notches. 5. Slot.
Do not force the pump assembly into the pump housing. Damage to the dowel in the lifter will result if the pump assembly is forced down.
5. When the fuel pump assembly is installed correctly the retaining bushing can be installed finger tight, flush with the top of the housing. If the bushing can not be installed this far finger tight, remove the bushing and pump assembly. Again align the components and again install the pump.
6. After the fuel pump assembly is installed correctly, tighten the bushing to 140 +10 or -5 lb. ft. (190 +14 or -7 N·m) with 8S4613 Wrench. Check total rack travel after each pump is installed. Refer to chart EXAMPLE OF RACK TRAVEL.
If one or more of the fuel injection pumps have been installed wrong, damage to the engine is possible if cautions are not taken at first starting. When the fuel injection pumps have been removed and installed with the fuel injection pump housing on engine, take the following cautions when first starting the engine.
a. Remove the air cleaner leaving the air inlet pipe open as shown.
AIR INLET PIPE
b. If a pump has been installed wrong and the engine operates in a not regular way, put a steel plate over the air inlet opening as shown to stop the engine.
STOPPING THE ENGINE
Fuel Injection Lines
Fuel from the fuel injection pumps is sent through the fuel injection lines to the fuel injection valves.
Each fuel injection line of an engine has a special design and must be installed in a certain location. When fuel injection lines are removed from an engine, put identification marks or tags on the fuel lines as they are removed, so they can be put in the correct location when they are installed.
The nuts that hold a fuel injection line to an injection valve and injection pump must be kept tight. Use a torque wrench and the 5P144 Fuel Line Socket (1) to tighten the fuel line nuts to 30 ± 5 lb. ft. (40 ± 7 N·m).
Fuel Bypass Valve
The fuel bypass valve controls fuel pressure to the fuel injection pump at full speed to a pressure of 30 psi (205 kPa).
Finding Top Center Compression Position For No.1 Piston
No.1 piston on the compression stroke at top center (TC) is the reference point for all timing procedures.
Remove the valve cover. The four valves at the front of the engine are the intake and exhaust valves for No.1 cylinder.
1. Rotate the flywheel clockwise (as viewed from the flywheel end of the engine) at least 30°. Now rotate the flywheel counterclockwise (as viewed from the flywheel end of the engine) until timing bolt can be installed in flywheel.
TIMING BOLT LOCATION (Engine without BrakeSaver)
1. Bolt to be used as timing bolt. 2. Plug.
NOTE: If timing hole is passed, do not back up, repeat Step 1 again.
2. Install bolt (1) through the opening for plug (2) and into the threaded hole in flywheel. All valves for No.1 cylinder should now be closed. If valves for No.1 cylinder are not closed, the flywheel must be rotated 360° counterclockwise until all valves are closed.
TIMING BOLT LOCATION (Engine with BrakeSaver)
1. Bolt to be used as timing bolt. 2. Plug.
3. After top center (TC) has been located, install bolt (1) and plug (2) back in their original locations before attempting to rotate the flywheel.
Fuel System Adjustments
Fuel Injection Pump Camshaft Timing
The fuel pump camshaft timing can be checked and reset, if necessary, in the following manner:
1. Locate (TC) compression position for No.1 piston. Refer to the topic FINDING TOP CENTER COMPRESSION POSITION FOR NO.1 PISTON.
TIMING PIN LOCATION
1. Cover. 2. Timing pin.
2. Remove timing pin (2) and cover (1). Install timing pin (2) back into the hole it was taken out of, until the end of the pin engages the timing slot in the fuel injection pump camshaft. Timing pin must be free in timing slot of camshaft.
3. If the timing pin will not engage the slot in the fuel injection pump camshaft, proceed as follows:
4. Remove the cover over the accessory drive housing. Loosen coupling bolts (3) retaining the accessory drive gear to the variable timing drive shaft. Retighten the coupling front bolt to 10 lb. ft. (14 N·m).
COUPLING BOLT LOCATION
3. Bolts (two).
5. Rotate the camshaft until timing pin (2) engages the timing slot in the fuel injection pump camshaft. Timing pin (2) must be free in the camshaft slot.
6. Remove timing pin (2) and the flywheel timing bolt. Tighten bolts (3) to 70 ± 4 lb. ft. (95 ± 5 N·m).
7. Rotate flywheel counterclockwise two complete turns (as viewed from the flywheel end) and insert timing bolt into flywheel timing hole.
NOTE: If flywheel timing hole is passed, do not back up, repeat Step 7.
8. Fuel injection pump camshaft timing pin should freely engage the timing slot in the fuel injection pump camshaft. If the timing pin does not engage the slot in the fuel injection pump camshaft, repeat the complete timing procedure.
Checking Fuel Injection Pump Timing - On Engine with 1P540 Flow Checking Tool Group
The timing dimension should be checked and reset, if necessary, to account for slipped variable timing drive coupling or worn timing gears.
Refer to Special Instruction (FM035709) for complete and detailed instructions for the fuel flow method of engine timing.
Travel of piston (6), from point of closing inlet port (5) to top center, can be found by using 3S2954 Timing Indicator Group. Convert the travel of piston (6) into degrees to determine if the timing is correct.
The 1P540 Flow Checking Tool Group is used to pressurize the fuel system. Maintain 10 to 15 psi (70 to 105 kPa) fuel pressure with the 1P539 Tank Assembly. This can be done with hand pump provided with the tank assembly, or connecting shop air to the tank assembly.
Be sure to make an adjustment to the regulator so the air supply in the tank is a maximum of 15 psi (105 kPa).
Consult chart to find angle corresponding to indicator reading. At the indicator reading and timing angle specified for this particular engine, fuel flow from the injection pump should be reduced to between 6 and 12 drops per minute [point of closing inlet port (5)].
Fuel Pump Timing Dimension Setting - Off Engine
- 6F6922 Depth Micrometer with 4" to 5"(101.6 to 127.0 mm) rod8S2244 Extractor8S4613 Wrench8S7167 Gauge1F8747 Plate Assembly (with 8S2346 Shaft)8S2348 Pointer Assembly
NOTE: The 1P5600 Timing Fixture Group can also be used. Form GMG00838 provides detailed instructions.
Use only the OFF ENGINE method to check and adjust a fuel pump timing dimension setting.
Proceed with off engine timing using an 8S7167 Gauge, 6F6922 Depth Micrometer, 4 to 5 in. (101.6 to 127.0 mm) rod, 1F8747 Plate Assembly (with 8S2346 Shaft in place of the standard 7F8751 Shaft) and an 8S2348 Pointer Assembly.
1. Install the 8S2348 Pointer Assembly on the fuel injection pump housing.
2. Install the 8S2346 Shaft on the drive end of the fuel injection pump camshaft.
4. Refer to the chart and select the timing plate degree setting for the lifter being checked or set. Set the timing plate by rotating it clockwise until the proper degree setting aligns with the pointer assembly. Lock in position with the lockscrew.
5. The fuel injection pump timing dimension (off engine), using the 8S7167 Gauge is 4.390 to 4.394 in. (111.51 to 111.61 mm).
6. The spacer must be changed to change the timing dimension.
7. If all timing dimensions are to be checked or reset, continue the same procedure in the firing order of the engine. Recheck each timing dimension after the adjustment has been made, to make sure the dimension is correct.
NOTE: At installation, the fuel injection pump camshaft must be timed to the engine crankshaft. See the topic FUEL INJECTION PUMP CAMSHAFT TIMING.
Checking Fuel Rack Setting
- 9S240 Rack Positioning Tool Group9S215 Dial Indicator8S4627 Circuit Tester
Rack settings are carefully set at the factory and should not be changed without specific instructions to do so. An incorrectly adjusted fuel rack affects the operation of the turbocharger.
PREPARING TO ADJUST FUEL RACK
1. Refer to the RACK SETTING INFORMATION to obtain the correct rack setting dimension.
2. Disconnect the governor control linkage, at the most convenient location, so the governor control lever moves freely throughout its entire length of travel.
3. Remove the fuel ratio control from the rear of the governor.
4. Remove plug (1) and washer from the housing.
5. Install 5P4814 Collet Clamp in the hole for plug (1).
6. Put a 9S8883 Contact Point on the 9S215 Dial Indicator. Put the dial indicator in collet clamp (3) and tighten the locknut of the collet clamp just enough to hold the indicator.
7. Move governor control lever to shutoff position. Loosen cover and depress rack centering pin so it engages the slot in the rack.
NOTE: Hold pin down in centered position, by placing the cover partially over the centering pin, and tightening the retaining bolt finger tight.
8. Depress the speed limiter plunger with 9S8521 Rod and 9S8518 Plug, and move the governor control lever toward the fuel-on position until the slot in the rack contacts the rack centering pin. The rack is now centered. Zero the dial indicator and remove rack centering pin.
9. Attach one end of the 8S4627 Circuit Tester to the brass screw terminal on the cylinder block side of the governor housing.
10. Rotate the governor control lever toward the fuel-on direction until the tester light comes on bright.
11. Slowly, rotate the governor control lever toward the shutoff position until the light goes out.
12. Now, again slowly rotate the governor control lever toward the fuel-on position, until the tester light just barely comes on (a dim light); rack collar is now just touching the stop bar. Rack setting can now be read directly from the 9S215 Dial Indicator.
13. If rack needs adjustment remove the governor housing rear cover, and refer to topic RACK ADJUSTMENT.
Move governor control lever to the shutoff position.
NOTE: Loosen locknut (1) and turn adjusting screw (2) with wrench (3) to adjust rack travel. Never adjust rack travel with shims.
Check adjustment performing Steps 7 through 12 in the topic CHECKING FUEL RACK SETTING. Continue adjustment procedure until the reading on the dial indicator is the same as the setting given in the RACK SETTING INFORMATION.
After the rack has been adjusted, tighten lock nut (1) to 9 ± 3 lb. ft. (12 ± 4 N·m).
ADJUSTING FUEL RACK
1. Lock nut. 2. Screw. 3. 4B9820 Wrench.
Only competent personnel should attempt to adjust the low and high idle rpm. The low and high idle rpm, and the rack setting dimensions for this engine, are listed in the RACK SETTING INFORMATION.
Engine rpm should be checked with an accurate tachometer.
Low and high idle rpm can be adjusted by removing the cover at the rear of the governor, and turning the high idle and low idle adjusting screws. Turning either adjusting screw in a clockwise direction will decrease the respective high and low idle rpm. The retainer holes in the cover are shaped to prevent the screws from turning, after the adjustment has been made.
After setting the idle rpm, move the governor control lever to change the engine rpm. Return it to the idle position and recheck the idle rpm. Repeat the adjustment procedure until the specified idle rpm is obtained.
1. Low idle adjusting screw. 2. High idle adjusting screw. 3. Cover. 4. Retainer holes (two).
Air-Fuel Ratio Control Installation
Before installing the fuel ratio control, adjust the fuel rack setting.
1. Install the bolt (3) in the notch (2) of the stop collar (1).
NOTE: It may be necessary to move the collar by rotating the governor control lever from fuel on to fuel off position. If more clearance is required to engage the notch, remove the cover retaining bolts and turn the cover (4) clockwise.
2. Install the bolts that hold the control to the governor cover.
3. Adjust the fuel ratio control setting. See the covering topic.
AIR-FUEL RATIO CONTROL INSTALLATION
1. Stop collar. 2. Notch in stop collar. 3. Bolt. 4. Cover.
Air-Fuel Ratio Control Setting (Air Activated)
- 9S240 Rack Positioning Tool Group.
The fuel rack must be set correctly before setting the fuel ratio control.
1. Remove the rack cover plug from the accessory drive housing, and cover (2) from the rear of the fuel ratio control.
2. Engage slot in cover (2) with cross-dowel in adjusting bolt and turn the adjusting bolt in as far as possible. This prevents the head of the bolt from limiting the travel of the fuel rack.
4. Remove the speed limiter access plug from the bottom of the governor and install plug (3). Through opening in plug (3) use rod (4) to push in (retract) the speed limiter plunger. Tighten plug (3) just enough to impose a clamping action on rod (4).
5. Center the rack and "zero" the dial indicator.
6. Move governor control lever (1) to FULL LOAD position. Hold the lever in the FULL LOAD position while making the adjustment.
7. Turn adjusting bolt out with cover (2) until the correct reading on the dial indicator is obtained. The correct reading is listed in the RACK SETTING INFORMATION.
8. Turn cover (2) clockwise the amount necessary to align bolt holes and install cover (2).
9. Remove the 5P4814 Collet Clamp and 9S215 Dial Indicator and install the rack cover plug.
10. Remove plug (3) and install the standard plug.
NOTE: Before starting the engine, make certain the governor control lever will move the governor to the SHUTOFF position and that all parts operate freely.
With the above initial adjustment made, a further adjustment can be made while the engine is running (if necessary) to improve engine performance. To reduce exhaust smoke during acceleration, turn cover (2) out (less fuel) 1/2 turn at a time until satisfactory. When exhaust smoke is acceptable but acceleration is sluggish, turn cover (2) in (more fuel) 1/2 turn at a time until satisfactory.
NOTE: Some exhaust smoke is likely to appear at maximum acceleration.
If acceleration is sluggish and full engine power seems to be lost, inspect the air line to the cover and the cover gasket for air leaks. If no air leaks are apparent, inspect the diaphragm. A damaged diaphragm will not allow the fuel rack to open completely, acceleration will be sluggish and full engine power cannot be obtained.
Hydraulic Air-Fuel Ratio Control Setting
1. The fuel rack setting must be correct before the adjustment for the hydraulic air-fuel ratio control can be checked or changed. Make reference to FUEL RACK SETTING.
NOTE: Use the 9S215 Dial Indicator from FUEL RACK SETTING to measure rack movement for air-fuel ratio control.
3. Remove the cover (3) from the hydraulic air-fuel ratio control.
4. Start the engine.
5. Push the end of valve (1) in and hold it in for two or three seconds. This action will manually move the valve into its operating position.
6. Move the governor lever from the "fuel off" to the "fuel on" direction several times to remove the air from the control for a more accurate reading.
7. Rapidly move the governor control lever in the "fuel on" direction and read the measurement on the dial indicator. Read the indicator carefully because this reading will be a maximum for only a moment. Look in the RACK SETTING INFORMATION to find the correct measurement.
8. To make an adjustment to the hydraulic air-fuel ratio control, turn valve (1) in a clockwise direction to make an increase in the limited rack position and in a counterclockwise direction to make a decrease in the limited rack position.
9. After each adjustment is made, the governor control lever must be moved from the "fuel off" to the "fuel on" direction before an accurate reading can be made.
10. After the correct adjustment has been made, put cover (3) in alignment with pin (2) in the valve and turn the cover to put it in alignment with the nearest bolt holes. Install the bolts.
11. Stop the engine.
12. After the oil pressure has gone out of the hydraulic air-fuel ratio control, full rack travel must be available. The speed limiter plunger will have to be pushed in to permit full rack travel.
HYDRAULIC AIR-FUEL RATIO CONTROL
1. Valve. 2. Pin. 3. Cover.
13. Now install the wire and seal on the control.
Air Inlet And Exhaust System
Restriction Of Air Inlet And Exhaust
Engine horsepower and efficiency will be reduced if either the air inlet or exhaust system becomes restricted.
The air cleaner should not restrict air flow more than 30" (762 mm) of water difference in pressure.
Exhaust back pressure (pressure difference measured between the turbocharger outlet elbow tap and the ambient air) should be no more than 27" (686 mm) of water, difference in pressure.
Measuring Inlet Manifold Pressure
By checking inlet manifold pressure, and comparing that pressure with the RACK SETTING INFORMATION, one can determine if an engine is operating efficiently. This test should be used if engine horsepower seems to be too low, yet no specific symptom of engine trouble is apparent.
Inlet manifold pressures in the RACK SETTING INFORMATION are recorded under specific operating conditions: 29.4 inches (746.76 mm) of mercury barometric pressure, 85° F. (29.7° C.) ambient temperature and 35 API rated fuel. Any deviation from these conditions can affect the inlet manifold pressure. Ambient air which is denser than that at 85° F./29.4 inches (29.7° C./746.76 mm) of mercury, can cause a slightly higher horsepower and inlet manifold pressure reading than listed in the RACK SETTING INFORMATION. If the ambient air is less dense, the horsepower and inlet manifold pressure rating can be slightly lower. Fuel density (API gravity rating) also affects the horsepower and inlet manifold pressure. If the fuel is rated above the standard 35 API gravity rating, the inlet manifold pressure can be slightly less than the value given in the RACK SETTING INFORMATION. If the fuel is rated below the standard rating, the inlet manifold pressure can be slightly more. BE SURE THE AIR INLET AND EXHAUST ARE NOT RESTRICTED WHEN CHECKING INLET MANIFOLD PRESSURE.
The components in a 4S6553 Instrument Group provide a means of reading engine rpm and inlet manifold pressure simultaneously. This group contains an instantaneous reading tachometer and a gauge for reading inlet manifold pressure. Special Instruction FEO36044 included with this group, explains the testing procedure.
INLET MANIFOLD PRESSURE TEST LOCATION
1. Plug (location to check inlet manifold pressure).
Exhaust temperature can be checked using the 1P3060 Pyrometer Group. Refer to the TOOL GUIDE. Special Instruction GMG00697 explains the testing procedure.
1P3060 PYROMETER GROUP
Excessive crankcase pressure can be a result of combustion gas leaking past broken or damaged pistons and/or piston rings. This condition will usually be accompanied by irregular engine operation and excess fumes from crankcase breather opening. This pressure can cause the breather element to become restricted in an unusually short time. In addition, it can cause engine oil to leak past gaskets and seals that would function properly under normal conditions.
Checking For Cylinder Compression Leakage
Irregular (rough) engine operation can be caused by incorrectly adjusted or leaky valves. Operate the engine at the rpm which makes the malfunction most pronounced. A non-firing or low compression cylinder can be located by loosening momentarily and then retightening fuel lines at the fuel injection pumps, one at a time, until a loosened fuel injection line makes little or no difference in engine operation. This same test can also indicate faulty fuel injection, so further checking of the cylinder is necessary.
1. Remove the fuel injection nozzle from the precombustion chamber in the cylinder head.
2. Adapt an air hose to the precombustion chamber. This can be done with either a threaded fitting or by holding a rubber adapter in place.
3. Rotate the crankshaft until the piston in the suspected cylinder is at top center (TC) on the compression stroke. In this position, the valves of this cylinder will be against their seats.
4. Force air into the cylinder and then check for escaping air. Air escaping from the exhaust opening indicates exhaust valve leakage and air escaping from the air inlet indicates inlet valve leakage. If air escapes from the crankcase breather during this test, the piston, rings and/or liner can be at fault.
It may be necessary to remove inlet and exhaust connections on both sides of turbocharger.
The intake and exhaust valves operate in replacement type valve guides. After the valves have been removed, clean the valve stems and valve guides.
If valve guides have to be honed after they are installed in the cylinder heads, use the 1P7450 Valve Guide Honing Arrangement. Special Instructions GMG00966 gives instructions for use of the 1P7450 Valve Guide Honing Arrangement.
Valve Guides With Shoulders
The bore of the 2M6414 Valve Guides must be .3751 ± .0007 in. (9.528 ± 0.018 mm), and the bore of the 9S9040 Valve Guides must be .3748 ± .0008 in. (9.520 ± 0.018 mm) after they are installed in the cylinder head. If the bore in the valve guides is smaller than the dimensions given after they are installed in the cylinder head, they must be honed.
Valve Guides That Do Not Have Shoulders
The bore of the 4N3665 Valve Guide must be a minimum of .3741 in. (9.502 mm), and the bores of the 4N3666 and 6N2236 Valve Guides must be a minimum of .3727 in. (9.467 mm) after they are installed in the cylinder head. If the bore in the valve guides is smaller than the dimensions given, they must be honed. Hone the valve guides to a size as close as possible to the minimum size. Do not hone the 4N3665 Valve Guide to a size larger than .3752 in. (9.530 mm), and do not hone the 4N3666 and 6N2236 Valve Guides to a size larger than .3737 in. (9.492 mm).
Valve Clearance Setting
NOTE: Valve clearance is measured between the cam and the cam follower. Follow this procedure to make an adjustment to the valve clearance:
1. Remove the valve cover.
2. Put No.1 piston at top center (TC) on the compression stroke and install the timing bolt in the flywheel. Make reference to FINDING TOP CENTER COMPRESSION POSITION FOR NO.1 PISTON.
TIMING BOLT INSTALLATION
3. Make an adjustment to the valve clearance on the intake valves for cylinders 1, 2 and 4 and exhaust valves for cylinders 1, 3 and 5.
4. Turn the cam followers on all of the valves until the angle hole in the follower is in alignment with the center line of the engine.
5. Put a Phillips screwdriver in this hole and turn the screwdriver clockwise to increase valve clearance or counterclockwise to decrease valve clearance. Use a feeler gauge to make a check of the valve clearance.
6. Remove the timing bolt. Turn the crankshaft 360° counterclockwise. Install the timing bolt in the flywheel.
7. Make an adjustment to the valve clearance on the intake valves for cylinders 3, 5 and 6 and the exhaust valves for cylinders 2, 4 and 6.
8. Remove the timing bolt from the flywheel and install it in its storage position. Install the plug in its correct position.
9. Install the valve cover.
TIMING BOLT STORAGE LOCATION
1. Timing bolt. 2. Plug.
1. Extreme caution should be exercised to be sure that all the camshaft followers are adjusted to provide maximum clearance before installation of the camshafts.
2. Rotate the crankshaft until No.1 piston is at top center on the compression stroke. Timing pin can be inserted into the slot in the fuel injection pump camshaft. See topic FUEL INJECTION PUMP CAMSHAFT TIMING.
3. Position the camshaft phasing gear timing marks (1) together and in a horizontal plane as shown.
CAMSHAFT PHASING GEARS
1. Timing marks.
4. Install the camshaft assembly.
5. Install the cam driveshaft with the blind spline on top.
6. Install the glow plug lead assembly and connect the leads to the glow plugs.
7. Adjust the valve clearance.
Every 200,000 miles 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.
End play for TV81 Turbochargers should be .003 to .010 in. (0.08 to 0.25 mm).
End play for T18 Turbochargers should be .004 to .009 in. (0.10 to 0.23 mm). End play for T12 Turbochargers should be .006 to .011 in. (0.15 to 0.27 mm). If end play is more than the maximum end play rebuild or replace the turbocharger. End play less than the minimum end play could indicate carbon build up on the turbine wheel and should be disassembled for cleaning and inspection.
CHECKING TURBOCHARGER ROTATING ASSEMBLY END PLAY
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.
CHECKING TURBOCHARGER RADIAL CLEARANCE
Radial clearance can also be checked with a dial indicator. Remove the oil return line from the turbocharger. Attach a dial indicator with an extension indicator point long enough to contact the shaft through the oil return hole. Make sure the contact point is centered on the shaft (highest indicator reading). Raise both ends of the shaft all the way then push down in the opposite direction. Total movement of the indicator should be between .004 in. (0.10 mm) and .009 in. (0.23 mm). If radial clearance exceeds .009 in. (0.23 mm) or minimum clearance is under .004 in. (0.10 mm), the turbocharger should be disassembled and the bearings checked.
NOTE: Care must be taken not to cock the shaft or a false reading will be obtained.
One of the problems in the following list will generally be an indication of a problem in the lubrication system for the engine.
TOO MUCH OIL CONSUMPTION
OIL PRESSURE IS LOW
OIL PRESSURE IS HIGH
TOO MUCH BEARING WEAR
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 is coming out of the crankcase breather. This can be caused by combustion gas leakage around the pistons. A dirty crankcase breather will cause high pressure in the crankcase, and this will cause gasket and seal leakage.
Oil Leakage Into Combustion Area of Cylinders
Oil leakage into the combustion area of the cylinders can be the cause of blue smoke. There are four possible ways for oil leakage into the combustion area of the cylinders:
- 1. Oil leakage between worn valve guides and valve stems.
- 2. Worn or damaged piston rings or dirty oil return holes.
- 3. Compression ring not installed correctly.
- 4. Oil leakage past the seal rings in the impeller end of the turbocharger shaft.
- 2. Worn or damaged piston rings or dirty oil return holes.
Too much oil consumption can also be the result of using oil with the wrong viscosity. Oil with a thin viscosity can be caused by fuel getting in the crankcase, or by the engine getting too hot.
Oil Pressure Is Low
An oil pressure gauge that has a defect may give an indication of low oil pressure.
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 (the sudden making of low pressure bubbles in liquids by mechanical forces) and a loss of oil pressure. Air leakage in the supply side of the oil pump will also cause cavitation and loss of oil pressure. If the bypass valve for the oil pump is held in the open (unseated) position, the lubrication system can not get to maximum pressure. Oil pump gears that have too much wear will cause a reduction in oil pressure.
Oil Filter and Oil Cooler Bypass Valves
If the bypass valve for the oil filter or oil cooler is held in the open position (unseated) and the oil filter or oil cooler has a restriction, a reduction in oil pressure can be result. To correct this problem, install a new Caterpillar oil filter.
Too Much Clearance at Engine Bearings Or Open (Broken or Disconnected Oil Line or Passage) Lubrication System
Components that are worn and have too much bearing clearance can cause oil pressure to be low. Low oil pressure can also be caused by an oil line or oil passage that is open, broken or disconnected.
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 running. The oil pressure of the engine will not get low just because the oil cooler has a restriction.
Oil Pressure Is High
Oil pressure will be high if the bypass valve for the oil pump can not move from the closed position.
Too Much Bearing Wear
When some components of the engine show bearing wear in a short time, the cause can be a restriction in an oil passage. A broken oil passage can also be the cause.
If the gauge for oil pressure shows enough good oil pressure, but a component is worn because it is not getting enough lubrication, look at the passage for oil supply to that component. A restriction in a supply passage will not let enough lubrication get to a component and this will cause early wear.
This engine has a pressure type cooling system. A pressure type cooling system gives two advantages. The first advantage is that the cooling system can have safe operation at a temperature that is higher than the normal boiling (steam) point of water. The second advantage is that this type system prevents cavitation (the sudden making of low pressure bubbles 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 an engine getting too hot is generally because regular inspections of the cooling system were not made. Make a visual inspection of the cooling system before testing with testing equipment.
Visual Inspection Of The Cooling System
1. Check coolant level in the cooling system.
2. Look for leaks in the system.
3. Look for bent radiator fins. Be sure that air flow through the radiator does not have a restriction.
4. Inspect the drive belt 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 pressure cap and the sealing surface for the cap. The sealing surface must be clean.
Testing The Cooling System
Remember that temperature and pressure work together. When making a diagnosis of a cooling system problem, temperature and pressure must both be checked. Cooling system pressure will have an effect on cooling system temperatures. For an example, look at the chart to see the effect of pressure and height above sea level on the boiling (steam) point of water.
Test Tools for Cooling System
- 9S9102 Thermistor Thermometer Group.9S7373 Air Meter Group.1P5500 Portable Phototach Group.9S8140 Cooling System Pressurizing Pump Group.
The 9S9102 Thermistor Thermometer Group is used in the diagnosis of overheating (engine running too hot) or overcooling (engine runs too cool) problems. This group can be used to check temperatures in several different parts of the cooling system. The testing procedure is in Special Instruction (GMG00450).
9S9102 THERMISTOR THERMOMETER GROUP
9S7373 AIR METER GROUP
The 9S7373 Air Meter Group is used to check the air flow through the radiator core. The testing procedure is in Special Instruction (GMG00203).
The 1P5500 Portable Photatach Group is used to check the fan speed. The testing procedure is in Special Instruction (GMG00819).
1P5500 PORTABLE PHOTOTACH GROUP
The 9S8140 Cooling System Pressurizing Pump Group is used to test pressure caps and pressure relief valves, and to pressure check the cooling system for leaks.
9S8140 COOLING SYSTEM PRESSURIZING PUMP GROUP
Gauge for Water Temperature
If the engine gets too hot and a loss of coolant is a problem, a pressure loss in the cooling system could be the cause. If the gauge for water temperature shows that the engine is getting too hot, look for coolant leakage. If a place can not be found where there is coolant leakage, check the accuracy of the gauge for water temperature. Use the 9S9102 Thermistor Thermometer Group or the 2F7112 Thermometer and 6B5072 Bushing.
Be careful when working around an engine if it is running.
Start the engine. The reading on the gauge for water temperature should be the same as the reading on the thermometer.
One cause for a pressure loss in the cooling system can be a bad seal on the pressure cap of the system. Inspect the pressure cap carefully. Look for damage to the seal or the sealing surface. Any foreign material or deposits on the cap, seal or sealing surface must be removed.
SCHEMATIC OF PRESSURE CAP
A. Sealing surface of cap and radiator.
Water Temperature Regulator
The regulator must be fully open at the following temperature:
4L7615 Regulator ... 180° F(82° C)
9S9160 Regulator ... 185° F(85° C)
1. Remove the regulator from the engine.
2. Put heat to a pan of water. Let the water become hot to the correct temperature that opens the regulator fully.
3. Hang the regulator in the pan of hot water. Put the regulator completely under the water. Do not let the regulator make contact with the pan.
4. Keep the water at the correct temperature according to the regulator, for 10 minutes. Make the water move in the pan. This keeps all the water at the same temperature.
5. Take the regulator out of the water.
6. Measure immediately the distance the regulator is open. The distance must be .375 in. (9.53 mm) or more.
7. Use a new regulator if the old regulator does not open correctly.
V-Belt Tension Chart
Connecting Rods And Pistons
Use 7M3978 Piston Ring Expander to remove or install piston rings.
Use 5P3526 Piston Ring Compressor to install pistons into cylinder block.
Tighten connecting rod bolts in the following Step sequence.
Piston Ring Groove Gauge
(Pistons That Use Keystone Rings)
Make reference to GUIDELINE FOR REUSABLE PARTS; PISTONS AND CYLINDER LINERS, Form No. SEBF8001 (Bulletin No. SEBF-8015).
The 5P4812 KEYSTONE PISTON RING GAUGE GROUP is necessary for measuring these grooves. Put the pin end of gauge "1" in the groove at four places around the circumference. Do this to both grooves. The flat edge of the gauge must be between the grooves. If there is clearance between the flat edge of the gauge and the piston at all test locations, for both grooves, the piston is reusable. If the flat edge is in contact with the piston, at any of the test locations, the piston is not reusable. Install a new piston.
5P4812 KEYSTONE PISTON RING GROOVE GAUGE GROUP
(Pistons With Straight Sides in Ring Grooves)
A 5P3519 Piston Ring Groove Gauge is available for checking ring grooves with straight sides. For instructions on the use of the gauge, see the GUIDELINE FOR REUSABLE PARTS; PISTONS AND CYLINDER LINERS, Form No. SEBF8001.
PISTON RING GROOVE GAUGE
Connecting Rod And Main Bearings
Bearings are available with a smaller inside diameter than the original size bearings. These bearings are for crankshafts that have been "ground" (made smaller than the original size).
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 torque shown in the SPECIFICATIONS. Alignment error in the bores must not be more than .003 in. (0.08 mm). The bores for the main bearings can be reconditioned through the use of a line bore procedure. Special Instruction (GMG-00503) gives instructions for the use of 1P4000 Line Boring Tool Group and 5P2381 Centering Rings making alignment in the main bearing bores. The 1P3537 Gauge Group can be used to check the size of the bores. Special Instruction (GMG00981) is with the group.
- 1P2396 Adapter Plate.8B7548 Push Puller Crossbar and three3H465 Plates3/4"-10 NC Bolts, 3 in. (76.2 mm) long.3/4"-10 NC Bolts, 7 in. (177.8 mm) long.7M7875 Head Bolt Washers.8S3140 Cylinder Block Counterboring Tool Arrangement.1P5510 Liner Projection Tool Group.
Check liner projection above top plate as follows:
1. Make certain that top plate (4) and the cylinder liner flange are clean.
2. Use 3/4"-10 NC bolts, 3 in. (76.2 mm) long, with two 7M7875 Washers (3) on each bolt to secure top plate (4) to the cylinder block. Place two bolts with washers on each side of the cylinder liner. Tighten the bolts evenly, in four steps; 10 lb. ft. (14 N·m), 25 lb. ft. (35 N·m), 50 lb. ft. (70 N·m) and finally to 70 lb. ft. (95 N·m).
SECURING TOP PLATE TO CYLINDER BLOCK (Typical Example)
1. 3H465 Plate. 2. 1P2396 Adapter plate. 3. Cylinder head bolt washers. 4. Top plate.
NOTE: To avoid moving bolts and washers as each liner is checked, install two bolts with washers on each side of each cylinder liner, along the entire length of the top plate.
3. Invert 3H465 Plate (1) from an 8B7548 Push Puller, in the center of adapter plate (2). Center crossbar (6) on the inverted 3H465 Plate. Using two 3/4"-10 NC bolts 7 in. (177.8 mm) long and two 3H465 Plates, secure the crossbar to the cylinder block as illustrated. Tighten the bolts evenly, in four steps; 5 lb. ft. (7 N·m), 15 lb. ft. (20 N·m), 25 lb. ft. (35 N·m) and finally to 50 lb. ft. (70 N·m). Distance from bottom edge of crossbar to top plate, must be the same on both sides of cylinder liner.
5. Measure liner projection as close as possible to the clamping area and at four locations around the liner. The liner projection must be within .0020 to .0076 in. (0.05 to 0.19 mm) and the four measurements should not vary more than .002 in. (0.05 mm). The average projection between adjacent cylinders must not vary more than .002 in. (0.05 mm).
MEASURING LINER HEIGHT PROJECTION (Typical Example)
5. Dial indicator. 6. Crossbar. 7. 1P2402 Block.
NOTE: If liner projection varies from point to point around the liner, rotate the liner to a new position within the bore. If still not within specified limits, move liner to a different bore.
NOTE: Measure and check the following dimensions when installing new parts. With all dimensions correct, proceed with the above listed Steps.
- a. Top plate thickness .5142 ± .0010 in. (13.061 ± 0.025 mm).
- b. Top plate gasket thickness, .008 ± .001 in. (0.20 ± 0.05 mm). (All surfaces must be clean and dry when installing gasket.)
- c. Cylinder liner flange thickness, .5252 to .5268 in. (13.340 to 13.381 mm).
- b. Top plate gasket thickness, .008 ± .001 in. (0.20 ± 0.05 mm). (All surfaces must be clean and dry when installing gasket.)
Liner projection can be adjusted by machining the contact face of the cylinder block with use of the 8S3140 Cylinder Block Counterboring Tool Arrangement. Form FM055228 is part of the cylinder block counterboring tool arrangement and gives tool usage information.
Shims of various thicknesses also are available to adjust liner projection.
Flywheel And Flywheel Housing
- 8S2328 Dial Indicator Group.
Heat the ring gear to install it. Do not heat to more than 400° F (204° C). Install the ring gear so the chamfer on the gear teeth is next to the starter pinion when the flywheel is installed.
Face Runout (axial eccentricity) of the Flywheel Housing
If any method other than given here is used, always remember bearing clearances must be removed to get correct measurements.
1. Fasten a dial indicator to the crankshaft flange so the anvil of the indicator will touch the face of the flywheel housing.
8S2328 DIAL INDICATOR GROUP INSTALLED
CHECKING FACE RUNOUT OF THE FLYWHEEL HOUSING
A. Bottom. B. Right side. C. Top. D. Left side.
2. Force the crankshaft to the rear before reading the indication at each point.
3. With dial indicator set at .000 in. (0.0 mm) at location (A), turn the crankshaft and read the indicator at locations (B), (C) and (D).
4. The difference between lower and higher measurements taken at all four points must not be more than .012 in. (0.30 mm), which is the maximum permissible face runout (axial eccentricity) of the flywheel housing.
Bore Runout (radial eccentricity) of the Flywheel Housing
1. With the dial indicator in position at (C), adjust the dial indicator to "0" (zero). Push the crankshaft up against the top bearing. Write the measurement for bearing clearance on line 1 in column (C).
2. Divide the measurement from Step 1 by 2. Write this number on line 1 in columns (B) and (D).
3. Turn the crankshaft to put the dial indicator at (A). Adjust the dial indicator to "0" (zero).
4. Turn the crankshaft counterclockwise to put the dial indicator at (B). Write the measurement in the chart.
NOTE: Write the dial indicator measurements with their positive (+) and negative (-) notation (signs). This is necessary for making the calculations in the chart correctly.
CHECKING BORE RUNOUT OF THE FLYWHEEL HOUSING
5. Turn the crankshaft counterclockwise to put the dial indicator at (C). Write the measurement in the chart.
6. Turn the crankshaft counterclockwise to put the dial indicator at (D). Write the measurement in the chart.
8S2328 DIAL INDICATOR GROUP INSTALLED
7. Add lines I and II by columns.
8. Subtract the smaller number from the larger number in line III in columns (B) and (D). The result is the horizontal "eccentricity" (out of round). Line III, column (C) is the vertical eccentricity.
9. On the graph for total eccentricity find the point of intersection of the lines for vertical eccentricity and horizontal eccentricity.
10. If the point of intersection is in the range marked "Acceptable" the bore is in alignment. If the point of intersection is in the range marked "Not Acceptable" the flywheel housing must be changed.
GRAPH FOR TOTAL ECCENTRICITY
Face Runout (axial eccentricity) of the Flywheel
1. Install the dial indicator as shown. Force the crankshaft the same way before the indicator is read so the crankshaft end clearance (movement) is always removed.
2. Set the dial indicator to read .000 in. (0.0 mm).
3. Turn the flywheel and read the indicator every 90°.
4. The difference between the lower and higher measurements taken at all four points must not be more than .006 in. (0.15 mm), which is the maximum permissible face runout (axial eccentricity) of the flywheel.
CHECKING FACE RUNOUT OF THE FLYWHEEL
Bore Runout (radial eccentricity) of the Flywheel
1. Install the dial indicator (3) and make an adjustment of the universal attachment (4) so it makes contact as shown.
2. Set the dial indicator to read .000 in. (0.0 mm).
3. Turn the flywheel and read the indicator every 90°.
4. The difference between the lower and higher measurements taken at all four points must not be more than .006 in. (0.15 mm), which is the maximum permissible bore runout (radial eccentricity) of the flywheel.
CHECKING FLYWHEEL CLUTCH PILOT BEARING BORE
5. Runout (eccentricity) of the bore for the pilot bearing for the flywheel clutch, must not exceed .005 in. (0.13 mm).
Damage to or failure of the damper will increase vibrations and result in damage to the crankshaft. It will cause more gear train noise at variable points in the speed range.
The vibration damper has marks (1) on the hub and the ring. These marks give an indication of the condition of the vibration damper. If the marks are not in alignment, the rubber part (between the ring and the hub) of the vibration damper has had a separation from the ring and/or hub. If the marks are not in alignment, install a new vibration damper.
1. Alignment marks.
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.
- 5P300 Electrical Tester.9S1990 or 1P7400 Battery Charger Tester.5P957 or 5P3414 Coolant and Battery Tester.
NOTE: Make reference to Special Instruction (GEG02276) and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical Tester.
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 charging. 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.
Never disconnect any charging unit circuit or battery circuit cable from battery when the charging unit is charging.
9S1990 BATTERY CHARGER TESTER
Load test a battery that does not hold a charge when in use. To do this, put a test load across the main connections (terminals) of the battery. For a 6, 8, or 12V battery, put a test load of three times the ampere/hour rating, (the maximum test load on any battery is 500 amperes). Let the test load remove the charge (discharge) of the battery for 15 seconds and immediately test the battery voltage. A 6V battery in good condition will show 4.5V; an 8V battery will show 6V; a 12V battery will show 9V. Each cell must show 1.6V on either a 6, 8, or 12V battery.
The Special Instruction (GEG00058) with the 9S1990 Battery Charger Tester gives the battery testing procedure.
- 5P300 Electrical Tester.
NOTE: Make reference to Special Instruction (GEG02276) and to the instructions inside of the cover of the tester, when testing with the 5P300 Electrical Tester.
The condition of charge in the battery at each regular inspection will show if the charging system is operating correctly. An adjustment is necessary when the battery is constantly in a low condition of charge or a large amount of water is needed (more than one ounce of water per cell per week or per every 50 service hours).
Make a test of the charging unit and voltage regulator on the engine, when possible, using wiring and components that are a permanent part of the system. Off the 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 operating condition.
Before starting the on engine testing, the charging system and battery must be checked as given in the Steps below.
1. Battery must be at least 75% (1.240 Sp. Gr.) full charged and held tightly in place. The battery holder must not put too much stress on the battery.
2. Cables between the battery, starter and engine ground must be the correct size. Wires and cables must be free of corrosion and have cable support clamps to prevent stress on battery connections (terminals).
3. Leads, junctions, switches and panel instruments that have direct relation to the charging circuit must give correct circuit control.
4. Inspect the drive components for the charging unit to be sure they are free of grease and oil and have the ability to operate the charging unit.
Alternator Regulator (Delco)
When an alternator is either overcharging or undercharging the battery, the alternator charging rate can be adjusted. Remove the hollow head screw from the cover of the alternator regulator and use a screwdriver to turn the inside adjustment. Turn the adjustment toward the "+" to increase or toward the "-" to decrease the alternator charging rate.
Pulley Nut of Delco-Remy Alternators
Tighten the nut that holds the pulley to a torque of 60 ± 5 lb. ft. (80 ± 7 N·m) with the tools shown.
Use a D.C. voltmeter to locate starting system components which do not function.
Turn the key switch ON. Turn the HEAT-START switch to the START position. Starting motor solenoid operation is audible as the starter motor pinion engages with the ring gear on the engine flywheel. The solenoid operation should also close the electric circuit to the motor. Attach one voltmeter lead to the solenoid terminal that is connected to the motor. Ground the other lead. Turn the HEAT-START switch to START and observe the voltmeter. A battery voltage reading indicates the malfunction is in the motor. It must be removed for further testing. No voltmeter reading indicates that the solenoid contacts do not close and the solenoid must be repaired or the starter pinion clearance should be adjusted to .36 in. (9.14 mm). See topic PINION CLEARANCE ADJUSTMENT.
A starting motor solenoid that will not operate may not be receiving battery current. Attach one lead of the voltmeter to the solenoid battery cable connection. Ground the other lead. No voltmeter reading indicates a faulty circuit from the battery. A voltmeter reading indicates further testing is necessary.
Continue the test by attaching one voltmeter lead to the starting motor solenoid small wire terminal and the other lead to ground. Observe the voltmeter and turn the HEAT-START switch to START. A voltmeter reading indicates that the malfunction is in the solenoid. No voltmeter reading indicates that either the series parallel switch is the fault or the HEAT-START switch does not close when turned to the START position.
Attach one lead of the voltmeter to the HEAT-START switch battery wire terminal and ground the other lead. A voltmeter reading indicates a defective switch. No voltmeter reading indicates further testing of the series-parallel switch is necessary.
A starting motor that operates too slow can be overloaded by excessive mechanical friction within the engine being started. Slow starting motor operation can also be caused by shorts, loose connections and/or excessive dirt within the motor.
Glow plugs can be checked with an ammeter. Disconnect the wire lead from the glow plug terminal on the HEAT-START switch. Install an ammeter, in series, between the disconnected lead and the terminal on the switch. Observe the ammeter with the HEAT-START switch turned to the HEAT position. Each 12 volt glow plug draws approximately 10 amperes. The ampere draw of one glow plug multiplied by the number of engine cylinders will be the total ampere draw of the glow plugs in the engine. A low reading is an indication of one or more defective glow plugs. Disconnect one glow plug lead at a time and observe the ammeter with the switch turned to HEAT. The disconnected glow plug that does not change the ammeter reading is the defective glow plug.
When no ammeter reading is obtained, test the HEAT-START switch. Attach one lead of the voltmeter to the glow plug wire terminal on the HEAT-START switch and the other lead to the ground. Observe the voltmeter and turn the switch to HEAT. No voltage indicates that the HEAT-START switch is defective.
Pinion Clearance Adjustment
Whenever 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.
Make the adjustment using the following procedure.
1. Install the solenoid without connector (1) from the MOTOR connection (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 battery to ground terminal (3).
PINION CLEARANCE ADJUSTMENT
4. Shaft nut. 5. Pinion. 6. Pinion clearance.
4. Connect for a moment, a wire from the solenoid connection (terminal) marked MOTOR to the ground connection (terminal). The pinion will move to crank position and will stay there until the battery is disconnected.
5. Push the pinion toward the motor end to remove free movement.
6. Pinion clearance (6) must be .36 in. (9.14 mm).
7. Pinion clearance adjustment is made by removing plug and turning nut (4).
Rack Shutoff Solenoid
Make the distance (1) between the shaft and the plate at the start of the test. Distance (1) for 3N548 Shaft is .59 in. (15.0 mm), and distance (1) for 6N4241 Shaft is .96 in. (24.4 mm).
1. Distance between shaft and plate. 2. Travel .62 in. (15.7 mm). 3. Starting position of plunger plate from mounting flange is .44 in. (11.2 mm) to measure travel of plunger.
Two checks must be made on the engine to give proof that the solenoid adjustment is correct.
1. The adjustment must give the plunger enough travel to move the rack to the fuel closed position. Use the 9S240 Rack Setting Tool Group to make sure the rack goes to the fuel closed position.
2. The adjustment must give the plunger enough travel to cause only the "hold in" windings of the solenoid to be activated when the rack is held in the fuel closed position. Use a thirty ampere ammeter to make sure the plunger is in the "hold in" position. Current needed must be less than two amperes.