0378179 JOHNSON GEAR & BUSHING Front

Engine Protective Devices
Inspect/Check
The engine protective shutoff controls must be inspected and checked for proper operation. This will ensure that if a malfunction should occur, the engine will stop without being damaged.Have the inspection and checks made by a qualified mechanic. Consult your authorized Caterpillar engine dealer, or refer to the Service Manual for your engine.Check air inlet valve to make sure it closes during testing.Crankcase Breather
Clean Crankcase Breather
If crankcase breathers are not serviced on a regular basis, they will become plugged. A plugged crankcase breather would result in excessive crankcase pressure that may cause crankshaft seal leakage.1. Loosen hose clamps (1) and slide the hose from the tube.2. Loosen clamp (2), remove breather (3) and the seal.3. Wash breather (3) in clean, nonflammable solvent and dry it.4. Install a new seal and breather (3). Tighten bolt clamp (2).5. Slide the hose on to breather (3) and tighten hose clamps (1).Fuel Filters
Do not fill fuel filter housings with fuel before installing elements. Contaminated fuel will cause accelerated wear to fuel system components.
The final fuel filter elements should be replaced when the fuel filter differential gauge registers 105 kPa (15 psi), when engine is at rated speed and operating temperature. The primary fuel filter should be cleaned each time the elements are changed.Changing Fuel Filters
1. Stop the engine.2. Shut off the fuel tank supply valve (if equipped). 3. Remove and discard the fuel filter element.4. Clean the gasket sealing material surface of the filter base. Make sure all of the old gasket material is removed.5. Apply clean diesel fuel to the fuel filter gasket.
Do not fill the fuel filters with fuel before installing them. This fuel would not be filtered and could be contaminated. Contaminated fuel will cause accelerated wear to the fuel system parts.
6. Install the fuel filter and tighten by hand until the filter gasket contacts the base. Tighten the filter 3/4turn more with a filter wrench.After changing the fuel filters, crank and start the engine. There should be enough residual fuel in the head to allow the engine to start. If the engine runs, and then stops, crank the engine for a period of 30 seconds, then allow the starter to cool for two minutes. If this cranking and cooling cycle does not start and run the engine, see the section "Priming the Fuel System".Priming the Fuel System
1. After changing the fuel filters, open the fuel supply line valve.2. Move the ON/OFF switch at the engine, to the OFF position. 3. Turn the pump handle knob counterclockwise. Release the lock plate from the retainer on the fuel priming pump.4. Operate the fuel priming pump until the air in the fuel system has been pumped through the fuel return line to the fuel tank.5. Start the engine. If engine misfires or there is excessive smoke, further purging of air from the fuel system is required.All Engines Not Equipped With a Fuel Priming Pump
On engines without a priming pump, prime the system by pouring clean, water-free fuel into the fuel filter housing. To do this, remove the plug on top of the mounting block.Pour fuel slowly into the filter housing allowing time for fuel to seep through the filter, manifold and injector lines. After the system is full, install the plug and crank the engine. The engine should start normally.