See Figures 1 and 2
The rear drum brakes are equipped with automatic adjusters actuated by the brake mechanism. No periodic adjustment of the drum brakes is necessary if this mechanism is working properly. If the pedal travel is greater than normal, it may be due to a lack of adjustment at the rear. In a safe location, drive the car backwards at low speed. While backing, pump the brake pedal slowly several times (neither the speed of the car or the speed of pumping the pedal has any effect on the adjustment, the idea is to apply the brakes several times while backing). Drive forward and check the pedal feel by braking from moderate speed. It may take 2 or 3 passes in reverse to bring the pedal to the correct travel; each brake application moves the adjuster very little.
If brake shoe-to-drum clearance is incorrect and applying and releasing the brakes in reverse does not adjust it properly, the parts will have to be disassembled for repair.
An alternate method of adjustment can be used when the brakes have been disassembled or when the reversing method does not work.
- Elevate and safely support the vehicle. If only the rear wheels are elevated, block the front wheels with chocks. Once the vehicle is firmly on stands, release the parking brake.
- Remove the rear wheels.
- Remove the brake drum. It will not come off if the parking brake is applied.
If the brake drum cannot be removed easily:
- Insert a screwdriver through the hole in the backing plate and hold the adjusting lever away from the star wheel.
- Using a brake adjusting tool, turn the wheel to reduce the tension (increase the clearance) on the brake shoes.
- Use a brake drum measuring tool with both inside diameter and outside diameter capability. Measure the inside diameter of the brake drum and record the reading.
- Measure the diameter of the brake shoe assembly at the friction surface. Use the adjusting wheel to adjust the brake shoes until the diameter of the shoes is 0.024 in. (0.6mm) less than the diameter of the drum. This small clearance is important; over-adjusted brakes cause drag and premature wear on the shoes.
- Install the brake drum(s) and install the rear wheel(s).
- Apply the parking brake and lower the car to the ground.
See Figures 3, 4 and 5
The correct adjustment of the brake pedal height, free-play and reserve distance is critical to the correct operation of the brake system. These three measurements interrelate and should be performed in sequence.Pedal Height
Measure the pedal height from the top of the pedal pad to the asphalt sheet. Correct distances are as follows:
- Wagons and 1984-1986 sedans-7.24-7.64 in. (184-194mm)
- 1987-1990 Sedans-5.79-6.18 in. (147-157mm)
- 1991-1994 manual transaxle sedans-5.63-6.02 in. (143-153mm)
- 1991-1994 automatic transaxle sedans-5.45-5.85 in. (138.5-148.5mm)
- If it is necessary to adjust the pedal height, loosen the brake light switch and back it off so that some clearance exists between it and the pedal arm.
On some models, it may be necessary to remove the lower dash trim panel and air duct for access.
- Adjust the pedal height by loosening the locknut and turning the pedal pushrod.
- On 1984-1990 models, return the brake light switch to a position in which it lightly contacts the stopper on the pedal arm.
- On 1991-1994 models, return the switch to a position in which it lightly contacts the stopper on the pedal arm, then back it out one turn. Check the clearance between the switch and the pedal. It should be between 0.02-0.09 in. (0.5-2.4mm). Adjust, if necessary.
- With the engine OFF , depress the brake pedal several times.
- Pedal free-play is the distance between the "at rest'' pedal position and the position at which the beginning of pedal resistance is felt. This represents the distance the pedal pushrod moves before actuating the booster air valve. Correct free-play is 0.12-0.24 in. (3-6mm) on 1984-1990 models and 0.04-0.24 in. (1-6mm) on 1991-1994 models.
- If necessary, adjust the pedal pushrod to achieve the proper free-play. After adjusting the free-play, recheck the pedal height.
- With the transaxle in PARK or NEUTRAL and the parking brake fully released, start the engine and apply normal braking effort to the pedal. Depress the pedal fully, but don't try to put it through the floor.
While the pedal is depressed, have an assistant measure the distance from the top of the pedal pad to the floor. Specifications are as follows:
- Wagons and 1984-1986 sedans-3.54 in. (90mm)
- 1987-1990 sedans-2.20 in. (56mm)
- 1991-1994 sedans-1.97 in. (50mm)
- The reserve distance can be greater than specified but must not be less. If the reserve distance is less than specification, the brake system must be diagnosed for leaks or component failure.