Fuel Filter: Description and Operation

Fuel Filter System:

The 6.2 liter diesel engine fuel system is composed of:

^ Fuel tank with water sensor and screen filter.
^ Primary fuel filter.
^ Mechanical fuel pump.
^ Secondary fuel filter.
^ Fuel line filter.
^ Injection pump.
^ High pressure lines and nozzles.

Fuel is pulled from the fuel tank by the mechanical fuel pump which is located on the right side of the engine. Fuel is pulled through the primary filter, by the mechanical pump. Fuel is then pumped through the secondary filter mounted on the inlet manifold.

Both filters remove foreign material which could damage the injection pump or clog the injector nozzle.
From the filter, the fuel is pumped to the injection pump.

The diesel engine has a water in fuel warning system allowing the user to guard against water in fuel, which is very critical to diesel engines. The fuel tank is equipped with a filter which screens out the water and lets it lay in the bottom of the tank below the fuel pickup. When the water level reaches a point where it could be drawn into the system, a warning light flashes in the cab. A siphoning system starting at the tank and going to the rear spring hanger on some models permits the user to attach a hose at the shut-off and siphon out the water.

The primary filter on the G van is mounted to the vehicle chassis right hand underbody cross sill forward of the fuel tank. The primary filter also has water draining provisions.

A secondary in line filter is the final filter before fuel enter the injection pump.