How to Clean Disc Brakes
Cleaning your disc brake pads and rotors is very important for proper braking performance, and it helps eliminate the dreaded brake squeal which is all too common on disc brakes.
Step 1: Get some Brakleen.
You can find this at an automotive store for cleaning car brakes, but it works just as well on your bicycle’s disc brakes. (You could substitute this with another similar brake cleaner or rubbing alcohol, but do not use a typical cleaner or degreaser which may leave a residue.)
Step 2: Wipe down the rotors.
Put some Brakleen on a clean rag and use that to wipe down both sides of the rotor. You could also spray the Brakleen directly onto the rotor, but try not to get it on any other parts, especially rubber seals.
Step 3: Spray the pads.
Spray some Brakleen right onto the brake pads themselves. This is easiest if you remove the pads from the caliper first.
Step 4: Let dry.
Let everything dry for a few minutes just to be safe, then reassemle and ride.
Isopropyl alcohol is the preferred cleaning agent for disc brakes as it evaporates quickly and leaves no residue