System Component Description

The park brake system consists of the following:

Park Brake Pedal Assembly: Receives and transfers park brake system apply input force from driver to park brake cable system.

Electric Park Brake (EPB) Module Assembly: Transfers park brake system apply input force from the Electric Apply Switch to park brake cable system.

Electric Park Brake Release Switch: Applied by the driver and activates EPB module or Electronic Stability Control (ESC) braking system.

Park Brake Release Handle Assembly: Releases applied park brake system when pulled.

Park Brake Cables: Transfers input force received from park brake pedal, through park brake cable equalizer, to park brake apply lever.

Park Brake Cable Equalizer: Evenly distributes input force to both the left and right park brake units. Threaded park brake cable equalizers are also used to remove slack in park brake cables.

Park Brake Apply Lever: Multiplies and transfers input force to park brake actuator.

Park Brake Actuator/Adjuster: Uses multiplied input force from apply lever to expand park brake shoe toward the friction surface of the drum-in-hat portion of the rear brake rotor. Threaded park brake actuators are also used to control clearance between the park brake shoe and the friction surface of the drum-in-hat portion of the rear brake rotor.

Park Brake Shoe: Applies mechanical output force from park brake actuator to friction surface of the drum-in-hat portion of the rear brake rotor.

System Operation

Park brake apply input force is received by the park brake pedal assembly being depressed, or by activating the electric park brake switch signaling the EPB module, and transfers an evenly distributed force through the park brake cables and equalizer to the park brake apply levers. The park brake apply levers multiply and transfer the input force to the park brake actuators which expand the park brake shoes toward the friction surface of the drum-in-hat portion of the rear brake rotors to prevent the rotation of the rear tire and wheel assemblies. The park brake release handle assembly releases an applied park brake system when pulled rearward.