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.
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, transferred and evenly distributed, through the park brake cables and
the park brake cable equalizer, to the left and right park brake apply levers. The
park brake apply levers multiply and transfer the apply input force to the park brake
actuators which expand the park brake shoe toward the friction surface of the drum-in-hat
portion of the rear brake rotor in order to prevent the rotation of the rear tire
and wheel assemblies. The park brake release handle assembly releases an applied
park brake system when it is pulled rearward.