The parking brake assembly is designed to apply the brakes mechanically to prevent the car from rolling when parked, or to stop the car in the event of a complete hydraulic failure. Most parking brakes operate on the two rear brakes. Some vehicles with front wheel drive have front wheel parking brakes. In these cases, in an emergency stop, most of the stopping power would be required on the front of the car.
The parking brake may be activated by a hand lever or a foot pedal. In either style, pushing the pedal or pulling the lever causes a cable connected to the rear brakes to be pulled. The cable has an equalizer so that the cable pulls the same amount on both left and right rear brakes.
The parking brake lever is connected to the secondary brake shoe. The lever is mounted on the back of the shoe and is connected to it by a pivot pin located in the upper end of the lever. The pivot pin is retained in the shoe by a washer and clip. The parking brake cable is attached to the lower end of the lever. A strut, located below the lever pivot pin, connects the lever to the primary brake shoe. The strut is notched at each end and is fitted into accommodating notches in the lever and primary brake shoe. An oval-shaped spring, installed on the primary shoe end of the strut, is used to position the strut.
When the parking brake is applied, the cable pulls the lower end of the parking brake lever forward, causing the connecting strut to push the primary brake shoe forward. At the same time, the upper end of the lever pushes the secondary brake shoe rearward. The combined action of the lever and strut expands the brake shoes, forcing them against the drum to develop brake action.