Here's a general guide. This is NOT a substitute for a repair manual specific to your vehicle. Always consult your repair manual for precise details and torque specifications. Variations exist between model years and trim levels.
Tools you'll likely need:
* Jack and jack stands (essential for safety!)
* Wheel chocks
* Lug wrench
* Socket wrench set (metric)
* C-clamp or brake caliper compression tool
* Brake pad shims (if replacing)
* Anti-seize lubricant
* Wire brush or sandpaper
* Penetrating lubricant (like PB Blaster)
* Safety glasses
* Gloves
Procedure:
1. Safety First: Park on a level surface, engage the parking brake, and chock the front wheels. Jack up the rear of the car and securely support it with jack stands. Never work under a car supported only by a jack.
2. Remove the Wheel: Remove the lug nuts and carefully take off the wheel.
3. Expose the Caliper: You should now see the brake caliper, brake rotor, and brake pads.
4. Compress the Caliper Piston: This is crucial. Use a C-clamp or a specialized brake caliper compression tool to push the piston back into the caliper. You'll need to turn the piston as you compress it, as it's likely a self-adjusting type. This creates space for the new, thicker brake pads. Be careful not to damage the piston seal. Some brake fluids may be expelled. Have rags ready.
5. Remove the Old Brake Pads: There are usually retaining pins or clips holding the brake pads in place. These may require a small punch or screwdriver to remove. Once removed, carefully take out the old brake pads. Inspect the caliper's slides and pins for rust or damage; clean and lubricate with a high-temp caliper grease if needed.
6. Inspect the Rotors: Examine the brake rotors for excessive wear or scoring. If they're excessively worn or damaged, they need to be replaced.
7. Install the New Brake Pads: Carefully install the new brake pads, ensuring they're properly seated in their slots. If shims were used before, make sure you replace them in the correct position.
8. Reinstall the Caliper: Carefully put the caliper back onto the rotor and over the new brake pads. Reinstall any retaining pins or clips.
9. Reinstall the Wheel: Put the wheel back on and tighten the lug nuts.
10. Lower the Vehicle: Carefully lower the vehicle using the jack.
11. Final Check: Tighten lug nuts fully. Check your brake fluid level; it may have lowered. Add brake fluid as needed (and only DOT 3 or DOT 4 brake fluid is appropriate).
12. Pump the Brakes: With the car still on jack stands, pump the brake pedal several times to make sure there is pressure and the brakes engage.
13. Test Drive: Carefully test drive the vehicle, paying close attention to the braking performance. If you notice anything unusual, immediately return to a safe location and check your work.
Important Considerations:
* Brake Fluid: Brake fluid is hygroscopic (absorbs moisture). If you're dealing with a significant brake fluid leak, you may want to consider flushing the brake system after the repair to remove moisture from the system.
* Rotor Replacement: If the rotors are worn or damaged, they'll need to be replaced as well. This usually requires a rotor turning tool or a special lug wrench.
* Caliper Issues: If the caliper piston doesn't move freely or there's significant corrosion, you might need to replace the entire caliper.
* Repair Manual: Obtain a repair manual specific to your 1994 Chevy Lumina Z34. This will provide detailed diagrams, torque specifications, and step-by-step instructions.
Remember, brake work is serious. If you're unsure about any step, it's far safer and more advisable to have a qualified mechanic perform the work. Improperly performed brake work can lead to severe injury or death.
