Description

Fig. 1 Electrical vacuum pump:

Some GM transverse mounted gasoline engine models are equipped with an external electrical vacuum pump which aids the power brake system at times of low engine vacuum. The system is comprised of an electric motor, hoses, a controller containing an internal on-off switch and a timer/relay. The pump is located under the battery in a plastic and metal casing, Fig. 1. Under normal conditions, the system works identical to conventional brake systems.