How Do I Install Rear Brakes on a '94 GMC Pickup?

The rear brakes on your '94 GMC pickup truck are servo-style drum brakes. As the brake shoes are expanded against the brake drum, they grab and try to follow the rotation of the drum. The rotation of the primary shoe wedges the secondary shoe against the anchor pin and drum, causing friction and deceleration of the truck. Replacing the shoes when they wear out is a common do-it-yourself auto repair project that requires basic brake repair tools.

Instructions

1

Park the truck on level ground and block both front wheels with wheel chocks. Raise the rear wheels using a floor jack positioned under the center of the rear differential and place jack stands under both rear axles. Lower the truck onto the stands for extra safety and support. Remove the wheels using a lug wrench.

2

Slide the brake drum off the rear axle and the brake shoes. Clean the brake shoes off using soapy water. If the drums are rusted to the axles, a few sharp blows from a hammer around the outer edge of the drum will loosen the rust and allow you to remove the drum.

3

Remove the return springs that attach the brake shoes to the anchor pin located at the top of the brake backing plate, using a brake return spring tool from the set. Place the tool over the anchor pin and rotate it until it slips the spring off the pin. Slide the parking brake bar, located below the wheel cylinder, out from between the brake shoes and lay it aside. Slip the adjuster cable off the anchor pin and lay it aside.

4

Remove the hold-down springs that attach the brake shoes to the backing plate, using a hold-down-spring tool from the brake tools set. Push the spring in with the tool and rotate it until it pops free from the pin that passes through it.

5

Twist the primary shoe and secondary shoe in opposite directions and allow the adjuster and lower anchor spring to drop free from the shoes. Remove the U-clip that attaches the parking brake lever to the secondary shoe using a pair of pliers. Remove the shoes from the backing plate and lay them aside.

6

Install the parking brake lever on the new secondary shoe using a new U-clip. Attach both new shoes to the backing plate, using the hold-downs springs and the hold-down-spring tool. Position the parking brake bar between the two shoes and slip the adjuster cable over the anchor pin.

7

Install the cable guide and return springs using the return-spring tool to pry the springs onto the anchor pin. Rout the adjuster cable around the cable guide and hook the end of it onto the adjuster lever. Attach the lower spring to the secondary shoe and the adjuster lever. Pull the two shoes away from each other at the bottom edge and slip the adjuster into position on the brake shoes.

8

Rotate the adjuster to expand it and the shoes until the drum will slide just over the shoes. Install the drum and reinstall the wheel. Repeat the process on the other rear wheel.

9

Adjust the brakes. Remove the rubber plug on the bottom edge of the back of the backing plate and insert the brake adjusting tool from the set into the slot. Rotate the adjuster downward until the drum rubs on the brake shoes slightly when the wheel is turned. Repeat for both sides.

10

Raise the truck off the jack stands and remove the stands before lowering the jack and the truck to the ground. Tighten the lug nuts securely with a lug wrench. Test drive the truck to verify that the brakes function properly.