GM Service Manual Online
For 1990-2009 cars only

Notice: Parking brake adjustment is not necessary. This is a self adjusting system and damage may result from attempting to adjust or modify this system in any way. It may be necessary to adjust the rear brakes to obtain the proper tension in the system.

The park brake system is applied by pulling up on the park brake lever. Applying the park brake lever places tension on the park brake cables, which actuates the rear park brake mechanism. The system mechanically forces the rear brake shoes against the brake drums, locking the rear brakes.