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Parking Brake System: Description and Operation

PEDAL

DESCRIPTION
The rear drum brake shoes serve as the parking brakes. The system made up of cables and levers attached to the rear brake secondary shoes. The front parking brake cable is connected to the parking brake pedal and to the rear cables. An intermediate cable is used on some vehicles to connect the front and rear cables. The parking brake pedal assembly is mounted on the driver side cowl panel. The front cable is directly attached to the assembly. The pedal assembly contains a spring loaded mechanism to hold the pedal in the applied position. A rod and spring are used to release the ratchet mechanism and return the pedal to normal position.

OPERATION
To apply the parking brakes, the pedal is depressed. This pulls the rear brake shoe actuating levers forward. As the actuating lever is pulled forward, the parking brake strut or cam (which is connected to both shoes), exerts a linear force against the primary brake shoe. This action presses the primary shoe into contact with the drum. Once the primary shoe contacts the drum, force is exerted through the strut/cam. This force is transferred through the strut/cam to the secondary brake shoe causing it to pivot into the drum as well.

A torsion locking mechanism is used to hold the pedal in an applied position. Parking brake release is accomplished by the hand release.

A parking brake switch is mounted on the parking brake lever and is actuated by movement of the lever. The switch, which is in circuit with the red warning light in the dash, will illuminate the warning light whenever the parking brake is applied. Parking brake adjustment is controlled by a cable tensioner mechanism. The cable tensioner, once adjusted at the factory, should not need further adjustment under normal circumstances. Adjustment may be required if a new tensioner, or cables are installed, or disconnected.