Vacuum Pump: Description and Operation

VACUUM PUMP

DESCRIPTION
The vacuum pump is operated by a slotted extension attached to the vacuum pump shaft. The vacuum pump shaft slotted extension fits into, and is driven by, the exhaust camshaft gear.
The vacuum pump is a constant displacement, vane-type pump. Vacuum is generated by vanes mounted in the pump rotor. The rotor is located in the pump housing and is pressed onto the pump shaft.
The vacuum pump rotating components are internally lubricated.
The vacuum pump is not serviceable and must be replaced as a unit. Do not disassemble or attempt to repair the pump.

OPERATION
Vacuum pump output is transmitted to the Heater, Electronic, Vacuum, Air Conditioner (HEVAC) and speed control, systems through a supply hose. The hose is connected to an outlet port on the pump housing and uses an inline check valve to retain system vacuum when vehicle is not running.
Pump output ranges from a minimum of 8.5 to 25 inches vacuum.
The pump rotor and vanes are rotated by the pump drive gear. The drive gear is operated by the exhaust camshaft gear.