All Fairmonts/Zephyrs have drum brakes on the rear wheels.
The major components of the system are the drum, the brake shoes, the brake shoe return and hold-down springs, and the automatic adjuster assembly. The rear brakes also incorporate a parking brake mechanism.
When the brake pedal is depressed, and hydraulic pressure is delivered to the wheel cylinder, the wheel cylinder expands to force the shoes against the drum. The primary shoe moves first, contacting the drum and pivoting slightly on its hold-down spring mounting pin. As the top of the primary (front) shoe contacts the drum, the bottom of the shoe moves slightly away from the drum. This movement is transferred through the adjusting screw to the secondary brake shoe, where it aids the wheel cylinder in bringing the secondary shoe in contact with the drum. Friction between the brake shoes and the drum causes the car to slow down and stop. When the brake pedal is released, the brake shoe return springs move the brakes away from the drum. If the lining on the brakes becomes contaminated or if the lining or drum becomes grooved, the engagement of the brakes and the drum will become very harsh, causing the brakes to lock up and/or squeal. If the brake shoes on one wheel contact the drum before the same action occurs in the outer wheels, the brakes will pull to one side when applied.
The automatic adjuster assembly consists of a cable, cable guide, adjuster lever, automatic adjuster spring, and adjusting screw. The automatic adjuster operates only when the brakes are applied while the car is backing up. When the brakes are applied with the car moving rearward, the movement of the secondary (rear) brake shoe (the automatic adjuster is attached to this shoe) causes the adjuster cable to pull the adjusting lever upward. When the brakes are released, the automatic adjuster spring pulls the adjusting lever downward. As the lever moves downward, it contacts the star wheel on the adjusting screw and pushes it downward. This causes the adjusting screw to unscrew slightly (expand) and move the brake shoes closer to the drum. The adjusting lever then rests on the star wheel of the adjusting screw until the brakes are applied the next time the car backs up. If the brake adjustment is OK, the secondary shoe will not have to move very far to contact the drum. This limited shoe movement will not lift the adjusting lever off the star wheel, thus the brakes will not be adjusted.
The parking brake mechanism in the wheel consists of a parking brake link and lever. The link fits between the two brake shoes. The lever is attached to the parking brake cable and the secondary brake shoe. When the parking brake handle is pulled in the car, the rear brake shoes are moved into contact with the brake drums.