This started recently and suddenly during our recent snow. It sounds like the pads have worn down. Only happens at very low speed, not immediately at the point where the disc brakes cut in (>7mph?). Apart from the sound, the braking action feels normal and it stops fine. The pads were only replaced a few months ago. Done 106,000 miles now, and no more than 2,000 since pads replaced. I had thought it might be some grit caught between disc and pads but it would have cleared by now and there are now obvious signs on the disc of anything. Any ideas or would I be best to remove the wheels and take a closer look. Also, is there a wear sensor on the pads?
Rusty brakes are common with the Prius. The brakes don't get enough use to keep them clean, so sometimes it helps to force the issue. Try this to clean the brakes and see if it helps: 1) On a clear road, accelerate up to around 50 mph. 2) Shift into N. 3) Apply the brakes (medium force) and slow to around 20 mph. 4) Shift back to D. 5) Repeat as necessary. Three or four braking passes should clean off the crud and get rid of the noise. Tom
