* Caliper slide pins: The most likely culprit. If the caliper slide pins weren't properly cleaned, lubricated, and moved freely during the brake job, they can bind. This binding causes the caliper to not move smoothly, leading to clicking and dragging (rubbing). The clicking is often a metallic sound as the pin catches and releases.
* Caliper piston: A sticky or slightly seized caliper piston can also cause similar symptoms. It might not be retracting fully, causing constant, light contact with the rotor, resulting in rubbing. The clicking might be the piston sticking and then releasing.
* Brake pad shims: These metal plates are often on the back of brake pads to reduce noise and vibration. If they weren't properly reinstalled or are damaged, they can create a clicking or rubbing sound.
* Rotor damage/warping: Though less likely if the rotors looked fine before replacement, a slightly warped or damaged rotor can create a rubbing sound, especially when braking. If the old pads had worn unevenly, this could have damaged the rotor.
* Improper brake pad installation: If the brake pads weren't seated correctly in the caliper, they could rub against the rotor or caliper.
* Loose hardware: A loose caliper bracket bolt or other fasteners could cause a clicking sound.
* ABS sensor: While less probable to cause consistent rubbing, a slightly dislodged ABS sensor could create a clicking sound, especially under braking. However, this is usually accompanied by ABS warning lights.
Troubleshooting steps:
1. Inspect the calipers: Carefully examine the caliper slide pins. Are they moving freely? Are they clean and lubricated? Try to manually move them back and forth. If they're sticky or seized, clean them thoroughly and lubricate with caliper grease (not general purpose grease).
2. Check the caliper pistons: Try to push the pistons back into the calipers using a C-clamp and a proper piston compression tool (avoid damaging the piston boot). Make sure they retract smoothly.
3. Inspect the brake pads: Ensure the pads are correctly seated in the caliper and that the shims are in place and not causing interference.
4. Inspect the rotors: Check the rotors for any warping or damage. A slightly warped rotor might need resurfacing or replacing.
5. Check for loose hardware: Ensure all caliper bolts and other fasteners are tightened to the manufacturer's specifications.
If you're not comfortable performing these checks, it's best to take the vehicle to a qualified mechanic to diagnose and resolve the issue. Ignoring brake problems can be dangerous.
