Troubleshooting › Noises
Brakes squeal or howl: causes and fixes
Squeal is vibration between the pad and the rotor or rim. Contamination and pad alignment cause most of it.
- Oil or grease on the pads or rotor · Most likely
Disc brakes: did lube or cleaner get near the wheel? Clean the rotor with isopropyl alcohol; contaminated pads must be replaced.
Fix: Fix squealing disc brakes · Replace disc brake pads · Replace hydraulic disc pads
- New pads or rotor not bedded in · Most likely
New parts squeal until bedded in: 10–20 firm stops from riding speed.
- Rim brake pads not toed in · Most likely
Rim brakes: with the front (leading) edge of each pad touching the rim, the back edge should be about 1 mm away.
Fix: Adjust V-brakes · Center and adjust a road caliper · Center a side-pull caliper
- Loose caliper bolts · Sometimes
Try the caliper mounting bolts. A loose caliper chatters and howls.
Fix: Center and adjust mechanical disc brake · Center a hydraulic caliper
- Dirty or worn rims · Sometimes
Rim brakes: wipe the braking track with alcohol and check the wear line.