0308688 JOHNSON WASHER, Front mount

Troubleshooting
Troubleshooting can be difficult. On the following pages there is a list of possible problems. To make a repair to a problem, make reference to the cause and correction.This list of problems, possible causes, and remedy, will only give an indication of where a possible problem can be, and what repairs are needed. Normally, more or other repair work is needed beyond the recommendations in the list. Remember that a problem is not normally caused only by one part, but by the relation of one part with other parts. This list can not give all possible problems and corrections. The serviceman must find the problem and its source, then make the necessary repairs.1. Engine Fails to Crank When Start Switch is Actuated2. Engine Cranks, but is Hard to Start or Fails to Start3. Engine Starts, but Engine rpm is Limited4. Misfiring5. Engine Speed Surges6. Low Power7. Excessive Vibration8. Heavy Combustion Knock9. Valve Train Clicking Noise10. Mechanical Knock11. Excessive Fuel Consumption12. Loud Valve Train Noise13. Oil in Coolant14. Little Rocker Arm Movement and Excessive Valve Lash15. Oil at the Exhaust (Slobber)16. Premature Engine Wear17. Coolant in Lubricating Oil18. Excessive Black or Grey Smoke19. Excessive White or Blue Smoke20. Low Engine Oil Pressure21. High Lubricating Oil Consumption22. Engine Overheats23. High Crankcase Pressure (Oil Blowing Out Breather)24. Engine Oil Diluted by Diesel Fuel25. Alternator Fails to Charge26. Alternator Charging Rate Low or Unsteady27. Alternator Charging Rate Excessive28. Noisy Alternator Fuel System
Difficulty within the fuel system can be caused by 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. See the topic, AIR INDUCTION AND EXHAUST SYSTEM for conditions that may cause lack of horsepower.Visual Inspection
1. Observe the fuel pressure gauge reading. Lack of pressure usually 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. Drain the water and sediment from the tank.3. Check for leakage in the fuel supply lines and components or for a kinked or restricted supply line.4. Replace the fuel filter elements.5. 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.6. Bleed the fuel system to remove trapped air.7. Test the fuel transfer pump.To test the fuel transfer pump, connect an 8M2743 Pressure Gauge which is part of 7S8875 Hydraulic Test Box in place of the fuel pressure gauge line at the filter housing.The pressure should be:Full load ... 30 5 psi(2.11 0.35 kg/cm2)Low idle ... min. 15 psi(1.05 kg/cm2)Cranking speed ... 10 to 15 psi(0.7 to 1.05 kg/cm2)Fuel Injection Service
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. (14.5 0.7 mkg), refer to SPECIFICATIONS for procedure. 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 housings can cause crankcase dilution, and result in low oil pressure, bearing wear, and engine damage.Testing Fuel Injection Equipment
Before attempting to test a fuel injection pump or valve in an engine that is misfiring or puffing black smoke, make a simple check to determine which cylinder is causing the difficulty. While operating the engine at a speed which makes the defect most pronounced, momentarily loosen a fuel line nut at the fuel injection pump sufficiently to "cut-out" one cylinder. Check all cylinders in the same manner. If, after cutting out a cylinder, there is no noticeable difference in engine operation, or if this action causes puffing of 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 Valves
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.The condition of a capsule-type nozzle assembly can be tested on the Caterpillar Diesel Fuel Injection Test Apparatus, and the nozzle leakage rate can be determined.Checking Fuel Injection Pump Lifter Washer and Pump Plunger
The timing dimension should be checked and adjusted, if necessary, with the fuel injection pump off the engine. 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.
These are patterns of wear between washer and plungers. 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 that 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