Squeaky Disc Brakes

[dhunt]

Hey my disc brakes, front and rear seem to squeak when moderate to hard braking is applied. Anyone got any ideas what causes this/how to fix it. It's more an anonnoyance than a problem but I wouldn't mind having a solution

Thanks

David

[Antallica]

Checked the amount of rubber left on the pads?

[Magua]

I've got the same problem on my front disc. Schreeces all the time, light, moderate, heavy breaking.

[Jackrat]

Give em' a good clean.
As long as the pad is good that works for me.
An old trick that I've seen done is to drill holes in the pad and put the carbon rod from an old D size battery into them.the last time I saw it done was in the seventys when jap disc's really were bad for it.

[Two Smoker]

I've got the same problem on my front disc. Schreeces all the time, light, moderate, heavy breaking.

Either you need new brake pads/shoes (which is most likely), or they are contaminated, therefore take them out and give them a good buff with a wire brush (preferably the one on the grinder) then lightly sand your disc or the inside of the drum with some P240-P300..... this should improve braking and stop the squeaking

[merv]

Squealing can also be caused by the interface between the back of the pad and the piston. This can be fixed by taking the pads out and lightly lubing the backs with "Copperslip" or equivalent - go and ask at Repco for some stuff to stop your brakes squealing and they will be able to sell you something. The copper based stuff like I use is designed for high temperatures. Whatever you do don't get any of it on the front surface of the pads.

[Magua]

Another trip to the bikeshop it is then.

[FROSTY:Me]

do not take the advise i gave a young bucket racer (in jest of course)and spray crc on your disk to stop the squeaking.
How was I to know he would be dumb enough to actually do it.
Still he got his revenge when he used me as brakes when suprisingly enough his diddn't work

[Motu]

Brakes squeak all the time - we just don't normaly hear it,so all we have to do is shift it out of our frequency,a scuff with emery and a clean in hot water will sort a glazed pad,assemble with ultra high temp lube on load points and pivots,lube,silicon or spray antisqueal adhesive on caliper contact surfaces will stop the pad moving and hence vibrating in use.

Jack mentions the graphite rod from a dry cell imbeded in a pad - ever see the mags on the front of a car discoloured with dark brake dust? - that's graphite,they put it in the pad material to lubricate the pad and stop squeal - sometimes nothing works and you just have to live with it,so long as everything is safe,just ignore it.

[pete376403]

Car discs are self lubricating to a certain degree* - cos they are cast iron -lots of carbon (graphite) in CI. Most bike discs are stainless, although some of the better bikes have CI discs, cos CI has a much higher coefficient of friction than stainless. Main reason Jap bikes use stainless is for appearances. CI disks will have a light coating of rust after a period (ie overnight) of non use. ignorant consumers don't like that, they'd rather have nice shiney disks even if they don't work as well.

Carbon fibre disks are a whole 'nother story. Need to be very hot before they start to work propoerly, so don't expect to see them on a mass produced street bike anytime soon.


*In spite of which, car disks can squeal like a stuck pig too. Copper-kote or similar thinly applied to the back of the pads helps.

[dhunt]

The basic impression I'm getting from everyones posts are, if the pads are ok then there is nothing wrong with the brakes. It just whether I can be bothered getting rid of the noise or not, correct?

David

[Magua]

Anyway to check if the pads are ok without taking anything apart?

[vifferman]

Anyway to check if the pads are ok without taking anything apart?

Well, you can usually see how much meat is left on them without taking them apart, by looking between the calipers (they're designed so that you can do that). But it's a small job to whip 'em off and check, and worth doing if you're serious about getting rid of the squeal.

[Jackrat]

Anyway to check if the pads are ok without taking anything apart?

Most are just held in with a clip or couple of pins.
Mine have a flip up plastic lid that you lift up to see the pads,have a good look around before you go to the shop.

[Posh Tourer :P]

The basic impression I'm getting from everyones posts are, if the pads are ok then there is nothing wrong with the brakes. It just whether I can be bothered getting rid of the noise or not, correct?

David

Thats pretty much it. Of course when you get down to metal it makes a more horrible metal on metal grinding. Definitely not squealing, which I cant seem to stop my pads doing. I clean them and two weeks later they are back at it....