For 1990-2009 cars

#### General Description

The booster is a tandem vacuum-suspended unit. Without the service brakes applied, the booster operates with vacuum on both sides of its diaphragms. When the brakes are applied, air at atmospheric pressure is admitted to one side of each diaphragm to provide power assist. When the brakes are released, the air is shut off from that side of each diaphragm. The air is then drawn from the booster through the vacuum check valve to the vacuum source.