Ask the Editors: Brake Pads on the Move
Everything here should be nice and snug.
When you say the pads won’t stay in place- are they just loose within the caliper or are they dragging? We’re going to assume the former though essentially it doesn’t matter, as the solution will be similar in either case.
Whenever replacing your brake pads (even if you’re replacing them with the same pads you took out), check to make sure you correctly reattached the keeper pins that hold the pads in place. If these are not providing adequate tension, the pads will move around inside the caliper.
If that checks out, you said you pushed the piston in? This is standard practice and makes fitting new (much thicker) pads back into the caliper necessary. However, now that the pads are in place, you should be able to get the piston to extend simply by pumping up the brakes. If it’s all assembled correctly, the hydraulic fluid should get the piston to push the pads directly onto the rotor then release them when you let go of the brake. If this piston is not responding, the first thing to do is to disassemble the caliper, clean and lube the assembly. If that doesn’t cut it, it’s time to replace the caliper.
If the piston is extending and the keeper pins correct, the only other possibility for pads moving freely in side the caliper are pads that are severely worn down. Replacement in this case should cure the situation. Hope this helps!
