Drum brakes on GMC trucks are found on the rear wheels of modern models while older trucks may have drums on both the front and the rear wheels. Drum brakes are more difficult to replace than disc brakes. When replacing drum brakes, you change out the shoes in the drum brake.
Instructions
- 1
Park the vehicle on a level surface and turn off its ignition. Set the two wheel chocks in front of the two front wheels. Loosen the wheel's lug nuts using the tire iron, turning counterclockwise. Raise the rear end of your truck with the jack and set the jack stands under both sides of the rear axle. Lower your truck onto the stands with the jack. Remove the lug nuts on your rear wheels with the tire iron. Slide the rear wheels off the the truck and pull the brake drum off the hub.
2Locate the adjuster spring on the top half of the brake assembly. Remove the spring with the pliers and detach the retractor spring that links the shoes.
3Slide out the rear-facing shoe manually, along with the adjuster lever and the assembly for the adjuster screw. Remove the parking lever from the brake shoe. Move the retractor spring to the side and remove the forward-facing shoe. Repeat the Steps 1 through 3 for the remaining wheel(s).
4Insert new brake shoes into both drums and reverse the instructions you followed above to restore all of the drum brake components to their original positions. Slide the drum back onto the wheel.
5Twist the star wheel on the adjuster screw clockwise with a flat-head screwdriver to tighten it and gain enough clearance for the drum to go over the shoes. Replace the vehicle's wheels and tighten the lug nuts by hand, turning clockwise. Lower your truck with the jack and remove the jack stands. Tighten the lug nuts with the tire iron.
