Brake squeal

[.Holdon.]

quick one, what is it and how do fix it?

[Chirpstr]

Could be he rotors that are worn down past the minimal specs or the pads are glazed.
Try rubbing the pads on a smooth bit of concrete in a circular motion.

[Calaber]

Another cause is cheap pads that are rock hard and never wear out. They are so hard, they actually squeal all the time and are murder on the discs.

If you have fitted these things (usually made in India or South East Asia), the solution is to find them a new home in nearest rubbish bin.

Even good quality pads can squeal because they are too hard. They are often made for competition use and are designed to operate at high temperatures. Normal street driving never gets them hot enough and the surface of the pad glazes (ie it gets a highly polished surface) and doesn't work well at all. The glazing causes the pads to squeal when the brakes are applied. You can "bust" the glaze as already stated above by removing the pads and rubbing them on a flat, smooth concrete floor, but if they glaze over again, they are probably too hard and need to head to the same bin as the cheapo's.

Some pads have grooves in them to help clear water and dust. If the dust builds up in that groove, it can cause squealing.

In the rear brakes, dust build-up in the parking brake is sure to cause squealing. Removing the discs, blowing out all the dust completely and refitting the discs will get rid of the squealing on most occasions. It is also worth checking the shoes to see that they are not worn to the point where they rub metal to metal on the braking surface of the hub.

[wikky]

Another cause (but not too common) is the pads can vibrate in the caliper, generating a high pitch squeal. This can be overcome by applying an anti-squeal paste or spray to the back of the pads.