Drum Parking Brakes
An integral parking brake system is part of the rear drum brake system. Parking brake systems like the one in the illustration use a cable, a lever, and a strut to apply the parking brakes. A cable is attached to the brake lever. The lever pushes the rear shoe outward, and the brake strut forces the forward shoe into the drum.
The secondary shoe faces the rear of the vehicle. In the illustration, you see that the parking brake strut is the member that acts upon the primary shoe. These two parts (cable | strut) work together to apply both the secondary and the primary shoes with equal force.
A self-contained drum parking brake system has a small parking brake that operates inside the hub of the rear brake rotors (Drum in Hat). They have similar characteristics as integral drum parking brakes, instead of hydraulic pressure, the driver uses a brake lever or pedal to apply mechanical pressure.