KIT-GASKET 6V7440 - Caterpillar

General Operation of the Fuel System
Refer to Systems Operation, "General Information" for locations of the components for the fuel system.
Illustration 1 g00918385
Diagram of the fuel system (1) Fuel tank (2) Emergency shutoff valve (3) Water separator (4) Fuel transfer pump (5) Fuel filter (6) Fuel injection pump (7) Fuel injection nozzles (8) Fuel return line from the fuel injection nozzles and the fuel injection pump to the fuel filter. (9) Fuel return line from the fuel filter to the fuel tank.When the engine is cranking, the fuel is pulled from fuel tank (1) through emergency shutoff valve (2) and through water separator (3) by fuel transfer pump (4). The fuel flows from fuel transfer pump (4) under low pressure to fuel filter (5). From the fuel filter, the fuel flows at low pressure to fuel injection pump (6). The fuel injection pump sends fuel at high pressure to each of the fuel injection nozzles (7). The fuel injection nozzles spray fuel into the cylinders. Leakage from the fuel injection nozzles and the fuel injection pump flows through fuel return line (8) to the inlet side of fuel filter (5). Excess fuel from the fuel filter flows through fuel return line (9) back to fuel tank (1) .Note: When the fuel goes through the water separator, any water in the fuel will go to the bottom of the bowl. The water can be drained through a valve which is located at the bottom of the bowl.The fuel injection pump needs fuel for lubrication. The precision parts of the pump are easily damaged. For this reason, the engine must not be started until the fuel injection pump is full of fuel that is free of air.The system must be primed when any part of the system is drained of fuel. The following list contains examples of both service and repairs when you must prime the system:
The fuel filter is changed.
Low pressure fuel line is removed.
The fuel injection pump is removed.
Fuel injection nozzle is removed.
The fuel tank is drained.
A leak exists in the low pressure side of the fuel system.The fuel transfer pump has a lever which is manually operated in order to remove the air from the fuel system. In order to release air from the system, a vent plug is located on the side of the fuel injection pump. The vent plug is loosened when the lever of the fuel transfer pump is operated in order to pump air through the vent plug.Governor
The fuel rack is connected to the linkage, which controls the fuel injection pump. This linkage is located in the timing case.These engines have a mechanical governor in order to control engine rpm. The governor operates for all engine rpm. The governor weight assembly is installed on the front of the gear of the camshaft. The other components of the governor are installed in the timing gear case.
Illustration 2 g00822233
Governor control mechanism in the timing gear case (1) Connection for the linkage to the fuel injection pump (2) Mechanical