F 150 4WD Pickup V8-5.4L CNG VIN M (2001)
Vacuum Brake Booster Check Valve: Description and Operation
Hose and Check Valve
The power bake booster check valve:
^
is located on the front of the power brake booster
^
is positioned between the power brake booster and the power bake booster hose.
^
closes when the engine is turned off.
^
in the dosed position, traps engine vacuum in the power brake booster.
^
retains vacuum to provide several power assisted brake applications with the engine off.
