Tools You'll Likely Need:
* Jack and jack stands (SAFETY FIRST: Secure the truck properly)
* Lug wrench
* Wheel chocks
* Socket wrench set (metric)
* Torque wrench
* Hammer (possibly a rubber mallet)
* C-clamp (possibly)
* Brake caliper piston compressor tool
* Wire brush or brake cleaner
* Penetrating lubricant (like PB Blaster)
Steps:
1. Safety First: Park on a level surface, engage the parking brake, and chock the front wheels. Raise the rear of the truck securely using a jack and support it with jack stands.
2. Remove the Wheel: Remove the lug nuts and take off the wheel.
3. Brake Caliper Removal: You'll need to remove the brake caliper. This usually involves:
* Locate the caliper mounting bolts: These are usually on the back of the caliper.
* Remove the bolts: Use the appropriate socket and carefully remove the bolts.
* Support the caliper: Use a bungee cord or wire to hang the caliper from something nearby. This keeps tension off the brake line and prevents damage. Do NOT let the caliper hang by the brake line.
4. Parking Brake Removal (If Applicable): This is the trickiest part, especially on older Sierras with integrated drum brakes inside the rotor. The process varies significantly depending on the year and model. The general steps include:
* Locate the parking brake adjuster: It's typically a star wheel or similar mechanism accessible through holes in the back of the rotor.
* Adjust the parking brake: Fully release the parking brake mechanism. This may require turning the adjuster. Your repair manual will show you exactly how to do this.
* Remove the parking brake shoes (if necessary): Some designs require removing the parking brake shoes to get the rotor off.
* Inspect the parking brake components: Check the condition of the shoes and the adjuster.
5. Rotor Removal: With the caliper and parking brake components addressed, the rotor should now come off. Sometimes it's just a matter of sliding it off the wheel studs. Other times, it may be stuck due to rust or corrosion. If stuck, try:
* Penetrating lubricant: Spray penetrating lubricant around the rotor's mating surface and let it soak.
* Gentle tapping: Use a rubber mallet to gently tap the rotor around its perimeter to break it loose. Avoid damaging the wheel studs.
* C-clamp (if necessary): In stubborn cases, a C-clamp can be used to gently pull the rotor off. Place the C-clamp across the rotor, using the wheel studs or other appropriate points as anchors.
6. Install New Rotor: Once the old rotor is off, clean the mounting surface of both the hub and the new rotor. Install the new rotor, making sure it's seated correctly.
7. Reassembly: Reverse the removal steps to reinstall the parking brake components, caliper, and wheel. Be sure to properly torque the bolts to the manufacturer's specifications.
Important Notes:
* Brake fluid: If you have to compress the brake caliper piston, be prepared to handle brake fluid. Use a clean container to collect any spilled fluid.
* Repair manual: The steps outlined above are general. Your vehicle's repair manual will provide precise instructions and torque specifications for your specific year and model of GMC Sierra.
* Professional help: If you're not comfortable with any of these steps, take your truck to a qualified mechanic. Brake work is crucial for safety.
Failure to follow proper procedures can lead to brake failure, which is extremely dangerous. If you're unsure about any step, seek professional assistance.
