Primary and Secondary Jet Pumps

Fig 1: View Of Primary & Secondary Jet Pumps

Courtesy of GENERAL MOTORS CORP.

The primary jet pump (1) is located in the primary fuel tank module. Fuel pump flow loss, caused by vapor expulsion in the pump inlet chamber, is diverted to the primary jet pump and the secondary jet pump (2) through a restrictive orifice located on the pump cover. The primary jet pump fills the reservoir of the primary fuel tank module.

Fig 2: View Of Secondary Jet Pump

Courtesy of GENERAL MOTORS CORP.

The secondary jet pump (1) creates a venturi action which causes the fuel to be drawn from the secondary side of the fuel tank, through the transfer pipe, to the primary side of the fuel tank.