Metal scraping noise from a hydraulic disc brake, diagnosis and fix
Check the brake pads before anything else.
- Answers
- Why is my bike's hydraulic disc brake making a metal scraping noise?
- Topics
- Amsterdam · bike · environment · health · lifestyle · mobility · sport
- Full article on willem.com
- https://willem.com/en/2021-01-10_commuter-bike-checkup/
Summary
A metal scraping sound under braking points to the brake pads. On my bike one pad had come loose because the fork keeping it aligned was out of place. Removing the wheel, inspecting the brake and fitting new pads fixed it.
Full text
The noise appeared on my commuter bike in freezing winter weather, when the roads were extra dirty from snow mixed with salt and sand. It came from the rear brake, a Shimano hydraulic disc brake that had never given me any problem. I removed the rear wheel from the frame to clear the brake and inspect the system properly, and found that one of the brake pads was loose: the fork that was supposed to keep it aligned was no longer in place, so metal was scraping on metal under braking. Replacing the pads is easy, just order replacements at your local bike shop. Pads come in different compounds that trade durability against how sharply they bite. For commuting I picked a hard, long-lasting compound.