For 1990-2009 cars

### Power Brake Booster

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

The power brake booster is a tandem vacuum suspended unit. The tandem vacuum suspended booster operates with vacuum on both sides of its diaphragms in a normal operating mode with the service brakes in the released position. Air at atmospheric pressure admits to one side of each diaphragm to provide power assist when the brakes apply. The atmospheric air shuts off from one side of each diaphragm when the brakes release. 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 booster are non-serviceable and are non-interchangeable.

### Power Brake Booster Vacuum Hose

The power brake booster vacuum hose provides 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.