REMOVAL & INSTALLATION
- Raise and safely support the vehicle.
- Remove the wheel and tire assembly.
- If equipped, remove the retainers from the wheel studs and discard; they do not have to be reinstalled.
Remove the brake drum. If the drum is difficult to remove, proceed as follows:
- Make sure the parking brake is released.
- Back off the parking brake cable adjustment.
- On 1990 through early 1992 vehicles, remove the access hole plug from the backing plate. On 1992-93 vehicles equipped with a knockout slug in the drum, use a hammer and a metal punch to bend in the backing plate knockout slug.
- Insert a suitable tool through the hole and press in to push the parking brake lever off its stop. This will allow the brake shoes to retract slightly.
- Apply a small amount of penetrating oil around the drum pilot hole. Use a rubber mallet to tap gently on the outer rim of the drum and/or around the inner drum diameter by the spindle. Be careful not to deform the drum through the use of excessive force.
- Inspect the brake drum and machine or replace, as necessary.
- Adjust the brake shoes and install the brake drum.
- Install the wheel and tire assembly and lower the vehicle.
Inspect the brake drums for cracks, scores, deep grooves, out-of-round and taper. Replace any drum that is cracked; it is unsafe for further use. Do not attempt to weld a cracked drum.
Smooth up any light scores. Normal, light scoring of drum surfaces not exceeding a depth of 1 / 16 in. (1.5mm) is not detrimental to brake operation. Heavy or extensive scoring will cause excessive brake shoe wear, and it may be necessary to machine the drum. When machining the drum, observe the maximum machine diameter specification.
If the brake shoes are slightly worn (but still usable) and the drum is grooved, polish the drum with fine emery cloth; do not machine it. Eliminating all drum grooves and smoothing the lining ridges would require removing too much metal and lining, while if left alone, the grooves and ridges match and satisfactory service can be obtained. However, if the brake shoes are to be replaced, a grooved drum must be machined. A grooved drum will wear a new brake shoe, resulting in improper brake performance.
An out-of-round or tapered drum prevents accurate brake shoe adjustment, and could possibly wear other brake parts due to its eccentric action. An out-of-round drum can also cause severe and irregular tire tread wear, as well as a pulsating brake pedal. Check for out-of-round and taper by measuring the inside diameter of the drum at several points using an inside micrometer. Take measurements at the open and closed edges of the machined surface and at right angles to each other. Machine the drum to correct out-of-round and taper, being careful to observe the maximum machine diameter specification.