Vacuum Brake Booster Check Valve: Description and Operation

The power brake booster check valve:
^ is located on the front of the power brake booster.
^ is positioned between the power brake booster and the power brake booster vacuum hose.
^ closes when the engine is turned off.
^ in the closed position, traps engine vacuum in the power brake booster.





^ retains vacuum to provide several power assisted brake applications with the engine off.