Left rear brake makes a squealing sound constantly ??

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e30newbie
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Mon Mar 22, 2010 12:16 pm

Hi guys,

There is a problem with the left rear brake. The wheel was removed and I can see a small part of the outer brake pad is touching the brake disc.

I think the squealing noise is caused by part of the brake pad touching the disc constantly.

Also there is one clearly visible gouge on the disc.

Do you guys think replacing the disc and brake pads will solve the problem or something is wrong with the caliper ?

Cheers
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steviec_lj
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Mon Mar 22, 2010 9:01 pm

Gouge on the disc will be an MOT failure, so best to replace before this is due. Will also increase your chances of stopping, or more like, stopping safely! Best to replace both sides at the same time too!!

Pads, depends how far gone they are.

After all that, it may be the caliper thats shot. Can't tell without a picture of it all.

Like pissing in the wind, you never know which direction it will take.
stonesie
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Mon Mar 22, 2010 9:11 pm

If the metal backing of the pad is on the disc then the pad is worn out and if the disc surface is damaged then that's buggered too.


New discs and pads for the rear I think, and clean the calliper carrier where the pads sit. When you fit the new stuff use copper grease on the ends and backs of the pads to stop them vibrating/squealing/seizing.

A picture would help us to give an accurate diagnosis from the other side of the world though :wink:
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Saga
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Tue Mar 23, 2010 10:04 am

As said, pics will help, but failing something more serious, the caliper's seized. If it was the pad retaining pins gone wrong, the pad shouldn't squeal constantly.

Pull the caliper off and check the movement of the piston + look for evidence of corrosion on or around the perimeter of the piston. Pull pads and check that the sliding rods move freely and are properly lubricated (and clean and relube). Even if the piston's seized, you can probably fix it by doing a careful rebuild using new seals and cleaning up corrosion and dirt in the bore and piston, as long as you're very gentle with the piston (no power tools!).

Depending on how bad the disc is, you may be able to use it. A little score line's not going to hurt it. Check the runout (garage can do this for you in about 5 minutes) as the disc may be uneven/warped if it's had a pad stuck on it for any length of time.
e30newbie wrote:Hi guys,

There is a problem with the left rear brake. The wheel was removed and I can see a small part of the outer brake pad is touching the brake disc.

I think the squealing noise is caused by part of the brake pad touching the disc constantly.

Also there is one clearly visible gouge on the disc.

Do you guys think replacing the disc and brake pads will solve the problem or something is wrong with the caliper ?

Cheers
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e30newbie
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Posts: 129
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Location: Australia

Thu Mar 25, 2010 1:58 pm

stonesie wrote:If the metal backing of the pad is on the disc then the pad is worn out and if the disc surface is damaged then that's buggered too.


New discs and pads for the rear I think, and clean the calliper carrier where the pads sit. When you fit the new stuff use copper grease on the ends and backs of the pads to stop them vibrating/squealing/seizing.

A picture would help us to give an accurate diagnosis from the other side of the world though :wink:
The pad is not worn out. The squealing sound stops when I apply the brake. The noise is not very loud but enough to piss me off. I will try to take some pics.

Cheers
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