Intermittent squealing brakes

[benson01]

Can anyone tell me what would make my brakes squeal intermittently? What causes squaling brakes anyway? never have known! I don't think it's anything squashed between the pads and the discs. Any help appreciated. My car is under warranty with Honda, but I would like to know a bit about the issue before I go into battle with them

Cheers.

[CarMad]

I have a feeling you might be needing new brake pads. Some manufacturers build a layer in just before the brakes are nearly gone that is designed make a noise as a warning.

I would try a few good hard stops to see if it might clear as well, you don't mention when it happens. I have heard of this happening just before you stop and that the problem goes after time.

Let us know what happens.

[Thorburn]

I used to get this and apparently it was air trapped between the pad and disc when one of them had worn a little unevenly causing some pitting which allowed air to become trapped under braking.

Might also be worth check the wear levels like CarMad says though..

[GTiMK5]

I have had this on a car too, I had new pads and discs and it still persisted. I cant remember exactly what the problem was but it was something to do with the one of the calipers and some seal which was knackered. Once this was sorted I never heard another squeak.

[benson01]

I suppose it could be a lot of things coudn't it! So best leave it to Honda to fix. There is no pattern to when I get the squeal. Mostly in the afternoons driving back from work for some reason, but can happen under soft or modest break force

[beez]

I had it yesterday, although I think it's stopped now. It could have been either:

Because they're brand new pads, just bedding in (I assume that's what the smell was)

or

Because I wore the old right wheel, right pad disc down to the steel and it grooved my disc (I should get a new disc soon..) so it could have been air trapped between the grooves and the pads.

I think your best bet is definately getting Honda to look at it.

[martin_longbow]

Are the pads new. Most have anti sqeel shims or something and it could be as simple as them not being fitted. If your not sure yourself get them checked and cleaned or renewed

[kerbside]

Brake squeal is most commonly caused by loose brake dust melting and causing the surface of the brake pad to become smooth. This is called glazing. The same can happen to brake shoes.

When the shiney surface of the pad contacts the shiney disc it vibrates at high frequency causing the noise.

As the brakes are allowed to cool the vibration (and the noise) are less apparent. The brakes may also be quieter in winter or if it is raining as the brakes run cooler and the dust does not melt as easily.

Removing the pads and roughening up the friction surfaces with some coarse sandpaper (on a flat surface) usually stops it.

For how long depends on the driver. Drivers who brake gradually or do lots of town driving generally have to suffer brake squeals more than people who brake hard and late or motorway drivers as this sort of driving usually cleans the pad surface and does not allow the brakes to heat up as much.

When new pads are fitted they can sometimes squeal too for similar reasons as above. This can be remedied by slapping some copper grease on the back of the pad. This acts as a damper and silences the noise.

If you are prone to noisy brakes it may be worthwile investing in a set of EBC greenstuff brake pads as these are made of different stuff and don't squeak. They generate less brake dust and are roughly the same as a set of 'genuine parts' pads.