Q: my 2010 honda odyssey vibrates when breaking downhill, had mechanic smooth rotors, continues every 2 years

Vibration on braking is typically due to excessive thickness variation in the brake rotor, pad defects, or excessive rotor runout as the rotor sits on the wheel hub. As installed on the wheel hub, rotor run-out should be measured by the mechanic using a dial indicator and verified to be less than .002 inches. If run-out exceeds .002 inches, the run-out must be corrected by shimming or re-indexing. If the rotors were turned or, worse, re-used as is, you could have excessive thickness variation in the rotor and that is a very common cause of vibration on braking. To have the root cause of the brake vibration identified, please request a brake and suspension system diagnostic and the responding certified mechanic will resolve this promptly. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.