annoying brake squeal - please go away

[kenlodge]

so...i recently replaced the pads, rebuilt the front caliper & M/C.
the squealing went away for a week or 2... but now it's back!

the disc seems in good condition.
the pads were purchased at Max BMW.
i scuffed the pads w/sandpaper before installation.
i took it easy on the pads for the 1st week or so, and have since done some hard braking - thanks to some jackass drivers & a bicyclist who weren't sure what red traffic lights are for.

how can i get rid of the annoying sqeeeal that i get when coming to a stop?

chamfer &/or sand the pads ? ?

[Bob_Roller]

If you can find a product called Disc Brake Quiet, made by Permatex, it works, it is a  spray on blue plastic coating that eliminates the vibration between the pad and piston .

Only  spray it on the back of the pad, it may cause the pads to stick if it gets between the pad and caliper .

Someone here also mentioned they used common rattle can auto paint on the pads with the same results .

[nhmaf]

Brake squeal is most often caused by the pads vibrating against the calipers. .You can try the "brake quiet" spray stuff available at most automotive parts stores to spray on the backs of rhe pads that may dampen things down.  Sometimes it works OK, sometimes not.   It is possible that your light usage of the pads for a week did not allow the pads to bed in well, and the may have glazed over.   I find the better way to bed in new brake pads when I replace them is to get out on a deserted back roads where I can get up to ~ 50 MPH or so and do several hard stops.  I'd take the pads off again and scuff them up again with same light sandpaper first.  Also make sure that you didn't inadvertently pick up a stone or something that is stuck in there and causing squeal or damaging things. Don't stay stopped for any length of time - accelerate back up to 50 MPH and do another hard stop, not allowing the brakes to cool off in between.

Do this 8-10 times or so. Then drive normally.   It brake pads are treated to gently they may not bed in properly.   IF this fails to improve things, try the spray stuff too.

[Julio A.]

I put copper grease on the backside of my pads; the side which contacts the caliper pistons; They work very well.

[Olliepup]

What is copper grease and what is it normally used for? Is it auto stores?
Dave

[montmil]

What is copper grease and what is it normally used for? Is it auto stores?
Dave

Thread lubricant. Yes.   Monte

[Bob_Roller]

Also referred to as anti-seize compound .

[Mike V]

It is possible that your light usage of the pads for a week did not allow the pads to bed in well, and the may have glazed over. I find the better way to bed in new brake pads when I replace them is to get out on a deserted back roads where I can get up to ~ 50 MPH or so and do several hard stops.  

Ken,

Good advice here from nhmaf. Even some (10 or 20) 30mph to 0mph stops may do the trick.  Allow some cooling in-between burnishing and find a safe place to do the stops as he mentions.

[RSMike]

When I got my bike 8 weeks ago and started riding it the pads were REALLY noisy, I did a fluid change, checked the pads (loads of wear left), roughed them up, did a good clean, and did the copper grease on the back of the pads trick mentioned by Julio ( this last one always worked for me on previous bikes, but none screeched as bad as the R65)

I think they might have been quiet for like about 5 miles, but then the screeching came back, My next plan was to replace the pads, however more pressing things needed attention first, and gradually as I have ridden the bike more, they have become somewhat quieter , so its now more like usual noisy brakes and not the ear piercing screeching that I originally had.

Monte noticed my skinflint ways with tyres http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1310295904,  , so no I'm thinking I will stick with these pads for another while, they stop fine at least and have plenty of wear to go.

[Barry]

What is copper grease and what is it normally used for? Is it auto stores?

Copper grease is real particles of copper in a high melting point grease. It's commonly available and used on brake parts for it's anti-seize properties and high temperature rating. It's been used for donkey's years as an anti squeal coating but is probably not as good as some more modern purpose made formulations. I use it because it's a good general anti-seize and I've always got some on the shelf. As well as the rear of the pads I apply the faintest smear to any part of the pad backing plate that is in sliding contact with the caliper. You don't want to get the stuff on any of the rubber parts though.

[steven m]

My twin disc setup squeals when the brakes are applied lightly.  If I apply more pressure the squealing goes away.  I used anti-squeal on the backs of the pads and it made no difference.  I have Brembo calipers.  Does this happen with the older ATE's as well?
Steve

[Bob_Roller]

My '81 with ATE calipers squealed until I put the plastic coating on the pads .

The '82 LS squealed until I replaced the OEM pads with EBC FA18 pads .

[Barry]

I'm using EBC FA18 pads and rarely have any problem with squeal.

[nhmaf]

I put on EBC FA18 pads last year, and they are doing some talking now this year - may be time to give them a quick swipe with some sandpaper and do the bedding in thing, followed by the spray goo on the backs if that does do the trick - I don't have any spray stuff on the backs of mine yet.

[kenlodge]

i took out the pads, scuffed them up well w/some sandpaper, put some lubricant on the backs of the pads... then gave them another break-in, doing some 50-0mph hard braking per some previous advice.  the squeal went away ...for a bit... it's always there, lurking, just waiting to be heard.  if i brake hard it seems to kill it for a while, but for "normal" braking it prefers the squeal to quiet braking.  may try some of that spray next, idk.  
or just deal w/the squeal.