Rear Wheel Disc

Fig. 1 Rear disc brake:

Fig. 2 Caliper housing cutaway to show parking brake mechanism:

Sliding caliper rear disc brakes are used on 1982---87 Lincoln Continental, 1984---87 Mark VII, 1987 Thunderbird Turbo & 1984---86 Mustang SVO Fig. 1. The caliper is basically the same as the larger front wheel caliper, however, a parking brake mechanism and a larger inner brake shoe anti-rattle spring have been added, Fig. 2. A hydraulically powered brake booster (Hydroboost) provides the power assist for this four wheel disc brake system.
The parking brake lever, located at the rear of the caliper, is actuated by a cable system similar to rear drum brake applications. When the parking brake is applied, the cable rotates the lever and operating shaft. Three steel balls, placed in pockets between the opposing heads of the operating shaft and thrust screw, roll between ramps formed in the pockets and force the thrust screw away from the operating shaft, in turn, driving the caliper piston and brake shoe assembly against the rotor. An automatic adjuster in the assembly compensates for lining wear and maintains proper clearance in the parking brake mechanism.
The cast iron rotors are ventilated by curved fins located between the braking surfaces and are designed to cause the rotor to act as an air pump when the vehicle is traveling forward. The rotors are not interchangeable and are identified by a Right or Left marking cast inside the hat section of the rotor. The rotor is secured to the axle flange in the same manner as a rear brake drum. A splash shield is bolted to a forged axle adapter to protect the inboard rotor surface.
The 1984 Mustang SVO four wheel disc brake system is the same as the Continental and Mark VII brake system, except that the Mustang SVO incorporates a vacuum booster.