What causes brake squealing?

[breakaway]

My front brakes on my CBR have always been good, especially since we put some new pads in (<2500K ago).

Now they've started making this horrible squeal - It's only there at low speeds though (Like walking speed) - sounds like someone is running their long nails down a board. Braking performance has not deteriorated, so far.

What's causing this?

I'll see if I can get a video but most likely won't be able to as the digital camera is currently on loan to mum who's overseas.

[xwhatsit]

Vibration. The pads get sort of a harmonic going at certain speeds.

That's what those flexible metal plates are behind the pads -- to damp the vibration. Dust etc. can also cause it. Give 'em a good clean out.

Lastly, if your pads are really low (like down to the backing material), then they'll make nasty noises and scratch the living shit out of your disc. But then your braking performance would be crap.

[breakaway]

Clean them out you reckon?

Does that mean taking it all apart again? Or will spraying some brake cleaner in there do the trick?

[EJK]

lube it with some vegetable oil :niceone:

jks lol

[FROSTY]

First place to look - youve glazed the pads up a bit.
Give thm a clean up with some 180 grit paper
use a flat surface of course

[Motu]

All brakes squeal - it's just out of our range of hearing that's all....dogs can hear your brakes if you can't.So all we have to do is shift it out of our range of frequency - easy for me as my hearing is so poor.Hard pads will squeal more than soft....so if I have a whinging customer who wants a perfect job but won't pay for new rotors or a machine,then they get cheap soft pads and are happy.

These days most workshops use anti squeal on every brake job - just glues the whole lot together so they can't vibrate.Also a lube with a high temp grease on the moving parts of the pad helps too.