The GMC Sierra has two different versions: the 1500 and 2500 series. Replacing the rear disc brakes on the two versions are basically the same with a couple of small differences. There are no special tools required and the process is relatively simple. Read further to learn how to replace the disc brakes on your Sierra in two hours or less.
Siphon approximately 2/3 of the brake fluid from the master cylinder reservoir with a syringe or suction gun. This is located under the hood on the passenger's side of the Sierra. Discard the used brake fluid in an approved container.2
Raise the Sierra from the ground with a car jack. Support the car on all sides with jack stands. Keep children and animals out of the vicinity while servicing the car to replace the rear disc brakes.3
Loosen the lug nuts of the rear tires with a torque wrench. Remove the wheels and set aside, face up, on the ground.4
Disconnect the caliper and hang it from the truck's frame with wire. Remove the caliper mounting bracket bolts from the backing plate. Slip out the brake pads then remove the clips and throw them away.
Install the new clips to the inside edges of the caliper mounting bracket, and then attach it to the backing plate assembly. If you replace the rear disc brakes on the 2500 series, be sure to clean the bolt threads with brake parts cleaner to remove the old glue from the adhesive patch before inserting them.6
Fasten one wear indicator to the inner pads and two wear indicators to the outer pads. Insert the brake pads onto the caliper mounting bracket. Attach the caliper mounting bracket bolts to the steering knuckle, and then tighten to 148 ft. lb. for the 1500 series and 122 ft. lb. for the 2500 series.7
Lay the caliper over the brake pads and connect the bolts. Torque the bolts to 82 ft. lb. Replace the tires and lower the vehicle to the ground.8
Replace the brake fluid, making sure to fill it to the proper level as indicated. Seat the brake pads by pumping the brake pedal in a slow but firm manner.