The power brake booster is a tandem vacuum suspended unit. The tandem vacuum suspended booster operates with vacuum on both sides of the diaphragms in a normal operating mode, with the brake pedal in the released position. When the brakes are applied, atmospheric air pressure is admitted to one side of each of the diaphragms to provide power assist . The atmospheric air is shut off from one side of each diaphragm when the brakes released. The air is then drawn from the booster through the power brake booster vacuum check valve to the vacuum source.

The internal components of the power brake booster are non-serviceable. The power brake booster is serviced as an assembly only. Do not attempt to disassemble the power brake booster.

The power brake booster vacuum hose supplies engine vacuum to the power brake booster for power brake assist applications. The power brake booster vacuum hose connects to the intake manifold with a threaded fitting and connects to the power brake booster through a pressed fit into the power brake booster grommet. The power brake booster vacuum hose contains two vacuum tees and contains a vacuum check valve. Service the two vacuum tees and the vacuum check valve separately from the entire hose assembly.