Operation CHARM: Car repair manuals for everyone.

Primer Fuel Pump

Immersed in the fuel tank, the primer pump delivers fuel to the main supply pump under a pressure equal to or above 2.5 psi, yielding an output of 116 qts. per hour. The primer pump is used for easier engine starting, by avoiding vapor lock in the fuel lines from the tank to the main pump. The primer pump is equipped with a separate fuel filter.