Fuel Pump: Description and Operation

Fuel Pump:

The electric fuel pump system consists of two fuel pumps: a low pressure boost pump mounted in the fuel tank, and a high pressure fuel pump mounted on the frame rail. An in-line reservoir is located at the high pressure pump inlet. This design provides for satisfactory fuel pump operation during extreme vehicle maneuvers and steep vehicle attitudes with low-tank fill levels.

The low pressure electric fuel pump is used to provide pressurized fuel to the inlet of the high problems. The inlet of the low pressure fuel pump has a nylon filter on it to prevent noise and hot fuel problems. The inlet of the low pressure fuel pump has a nylon filter on it to prevent dirt and other particulate matter from entering the system. Any water accumulation in the fuel tank can pass through the filter without restriction.

Fuel Pump:

The externally mounted high pressure fuel pump is capable of supplying 80 liters (21.2 gallons) of fuel per hour. The pump has an internal pressure relief valve to provide overpressure protection in the event the fuel flow becomes restricted. Overpressure is restricted to 950 kPa (138 psi) and reduced fuel flow will result. The system pressure is controlled by a pressure regulator on the engine.