Here's how to approach it:
1. Safety First: Always engage the parking brake firmly and chock the front wheels. Wear safety glasses. Brake fluid is corrosive, so protect your paint and skin.
2. Remove the Caliper: You'll need to remove the caliper from the caliper bracket. This usually involves:
* Removing the caliper mounting bolts (usually two).
* Carefully supporting the caliper with a wire or bungee cord to avoid putting stress on the brake hose. Do *not* let the caliper hang by the brake hose.
3. Compress and Rotate: This is the tricky part. Several tools can help:
* Caliper Compression Tool: This is the best option. These tools are designed to both compress and rotate the piston. They're relatively inexpensive and available at most auto parts stores. Make sure you get one that's compatible with a self-adjusting piston.
* C-Clamp and Socket: A C-clamp with a socket (the correct size to fit against the piston) can work, but you'll need to carefully rotate the piston manually as you compress it. This requires patience and coordination, as you don't want to damage the piston or seal. Use a piece of wood or a proper adapter between the C-clamp and the piston to prevent damage.
* Professional Assistance: If you're not comfortable doing this yourself, take it to a mechanic. It's a relatively quick job for a professional.
4. Brake Fluid: As you compress the piston, old brake fluid will be pushed out. Be prepared to catch this with a rag or container. Never let your brake fluid reservoir overflow.
5. Reinstallation: Once the piston is fully compressed and the new pads are in place, reinstall the caliper, bleed the brakes, and test thoroughly.
Important Considerations:
* Seized Piston: If the piston is seized or extremely difficult to move, don't force it. You risk damaging the piston or seal. A penetrating lubricant (like PB Blaster) *might* help, but only apply it carefully and give it time to work. A seized piston is often a sign of other problems with the caliper or brake system. Replacing the caliper might be necessary.
* Brake Bleeding: After compressing the piston and reinstalling the caliper, you *must* bleed the brakes to remove air that's entered the system. This is crucial for safe braking.
* Correct Pads: Make sure you have the correct brake pads for your vehicle. Using incorrect pads can cause problems with braking performance and caliper wear.
If you're unsure about any step, consult a repair manual specific to your 1997 Cadillac DeVille or seek professional help. Working on brakes is critical for safety; don't hesitate to get assistance if needed.
