Test C: The Parking Brake Will Not Release Using The Automatic Parking Brake Release

Pinpoint Test C: The Parking Brake Will Not Release Using the Automatic Parking Brake Release

Normal Operation
Vacuum is supplied to the vacuum switch at all times (a vacuum reservoir supplies the vacuum when the engine is not running). When the transmission selector lever is placed in DRIVE, a tab on the selector lever actuates the vacuum switch which supplies vacuum to the vacuum actuator. When vacuum is supplied to the actuator, it moves a lever that is connected to the parking brake control and releases the parking brake.

This pinpoint test is intended to diagnose the following:
^ Vacuum tube(s)
^ Vacuum switch
^ Vacuum actuator
^ Actuator lever

C1-C4:

C5: