Tools You'll Need:
* Jack and jack stands (Crucial for safety)
* Wheel chocks
* Lug wrench
* Socket wrench with various sockets (likely 13mm, 15mm, and possibly others depending on your caliper design)
* Ratchet
* C-clamp or brake caliper compression tool
* Pliers or wire cutters (for retaining clips)
* Brake cleaner
* Penetrating lubricant (like PB Blaster)
* New rear brake pads
* Gloves
* Safety glasses
Procedure:
1. Safety First: Park on a level surface, engage the parking brake, and chock the front wheels. Use jack stands to securely lift the rear of the car. Never work under a car supported only by a jack.
2. Remove the Wheel: Loosen the lug nuts with the lug wrench before jacking up the car. Once the car is safely supported on jack stands, remove the lug nuts completely and take off the wheel.
3. Expose the Caliper: You'll now see the brake caliper, brake rotor, and brake pads.
4. Compress the Caliper Piston: This is the most critical step. The caliper piston needs to be compressed to create enough space to install the new brake pads. Use a C-clamp or a brake caliper compression tool to carefully push the piston back into the caliper. Do this slowly and evenly to avoid damaging the piston seal. Some pistons rotate as they compress; you may need to rotate it as you push. You might need to use penetrating lubricant to help the piston move. Note: If your calipers have bleeder screws, it's often easier to open them slightly while compressing the pistons to allow trapped brake fluid to escape. Consult a repair manual if you choose to do this, as you'll want to be prepared to catch the fluid.
5. Remove the Old Brake Pads: Depending on the design, you might need to remove retaining pins or clips holding the brake pads in place. Use pliers or wire cutters to carefully remove these. Then, slide out the old brake pads. Inspect the brake rotor for excessive wear or damage.
6. Install the New Brake Pads: Carefully insert the new brake pads into the caliper. Ensure they slide in easily. Replace any retaining pins or clips.
7. Reinstall the Wheel: Put the wheel back on and tighten the lug nuts. Don't fully tighten them yet.
8. Lower the Vehicle: Slowly lower the car using the jack.
9. Tighten Lug Nuts: Once the car is on the ground, fully tighten the lug nuts in a star pattern.
10. Repeat for the Other Side: Repeat steps 2-9 for the other rear wheel.
11. Test the Brakes: Carefully test the brakes several times. You should feel a firm pedal. If the pedal feels spongy or soft, you likely have air in the brake lines and need to bleed the brakes (this is a more advanced procedure).
Important Considerations:
* Repair Manual: A repair manual specific to your 2004 Pontiac Grand Prix is highly recommended. It will provide detailed diagrams and instructions, making the process much easier and safer.
* Brake Fluid: If you opened the bleeder screws, you may need to add brake fluid to the master cylinder reservoir.
* Brake Rotor Condition: Inspect your brake rotors. If they are excessively worn or scored, they will need to be replaced or resurfaced.
* Caliper Condition: Examine your calipers for leaks or damage.
* Professional Assistance: If you are unsure about any part of this procedure, it's best to seek professional help. Brake failure can be dangerous.
This information is for guidance only. Always consult a repair manual specific to your vehicle for detailed instructions and safety precautions. Incorrectly performing brake work can have serious consequences.
