[biosurfer1]

I have an intermittent problem when braking I'm hoping to solve. Once in a while I get a squeal when I brake and what feels like a grinding. I can't really tell exactly where it's coming from but it sort of feels like its coming from the front of the car. I went through each wheel carefully and checked all the pads and rotors and everything looks to be fine. No scoring in the rotors, plenty of pad left all the way around so I'm at a loss for what it could be?



The noise.grinding is not always there, but more often than not it is. I'm 99% sure it has something to do with the brakes because it only happens when I brake and it is more pronounced when I brake normally but dies down the harder I brake.



Any thoughts on where to start looking would be a big help...thanks!

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[flash]

when you say "plenty of pad" how thick are they?

what kind of pad are they?

are the rotors drilled?

are the calipers covered in brake dust?

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[biosurfer1]

I don't have the pad measurements with me, I'll get them later tonight. To answer what I can, yes the rotors are drilled and yes, everything is covered it brake dust. I blew everything out with compressed air (lots of dust everywhere) but it didn't make a difference but didn't expect it to.

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[Cloud9...68]

I was once getting a strange intermittent noise (though more or a higher pitched screeching type sound) during braking. After some searching, I found a small rock had lodged itself between the dust shield and the spindle (iirc - it was several years ago). It wasn't doing any harm, just making a racket. So you may want to really get your head up into the works with a good flashlight and look for any sign of foreign matter, and stick you hand up all around there to see if you can feel anything. Good luck.

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[flash]

yup



pull the wheels and spray down the calipers and such with brakleen too.



frankly though i'm suspecting the rotors and/or pads are glazed.

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[biosurfer1]

I'll post some pictures tonight. Never had to deal with glazing before. Is the only answer to get new rotors or have them turned if it turns out to be the problem?

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[Qfrank]

I am with flash, glazing.



I have had a "scrubbing/scratchy" sound from time to time, more at low speeds from the front.



Stock rotors, and stock pagid pads, excellent condition. My car sits for a month or more, and it will do it from time to time, unless i get hard on the brakes from 65mph down a few times once hot. Autocrossing stop it as well.



You could just pull,the pad out and scrub on smooth concrete, or hit with 60 grit sandpaper, and keep,them as clean as possible..



FQ

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[Inkedupfatboy]

I had a squeal and grinding noise in my car once...It went away when I divorced her - lol





http://instantrimshot.com/

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[flash]

scuffing the pads won't likely help for long, and the noise will come back. it's a materials thing. once pads or rotors are glazed, they're done.



i'd be carefully inspecting things first. there could be foreign objects in there.

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[ds968]

My rotors and pads are glazed ( after 60,,000 miles on both tne rotors are essentially " out of the box new " with not the slightest lip or hairline grooves anywhere and the pads have only about 25 % wear ) but they are dead silent - not a squeak, squeal, nada ! And absolutely zero brake dust ! Now, Flash drove the car ( as did another forums member and local friend ) and both said the stopping power SUCKS ! It seems perfectly fine to me, its much better than my MBZ and never had a problem with braking whatsoever but I suppose by comparison to how the brakes SHOULD be in this car, it does suck. Anyway, back to the point : gazing does not necessarily generate noise.

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[flash]

correct. it can show up in a few different ways. it can be slippery, as in the case with ds968. it can make noise. it can produce judder. the latter is commonly misdiagnosed as warped rotors. in over 30 years of dealing with cars and their upkeep, including owning and running a shop, and working on a few race teams, i have seen a grand total of 3 warped rotors. but i've seen plenty that were glazed.



there is a chemical reaction that happens when pads and rotors heat up and cycle. they "break in" to each other. that's why you can't mix and match pads on the same rotor. even if you use track pads to "scuff" the rotor, it has still be set for the other pads.



stoptech has a LOT of information on all of the things brake related. it's a great site and everybody should visit it to learn.

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[craigawoodman]

What about the small metal shims at the back of the pad? Are these there? Aren't these to help stop brake squeal? Don't ask me how these stop squeal, but it was what I was told (along with making it easier to get the pads out once worn).



Most new pads come with a new set of these shims.

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[biosurfer1]

Thanks guys for all the replies. Going to take me a little bit longer to look into this as my wifes business has a fair this weekend and guess who got "volunteered" to help watch the booth <img src="/forum/images/smilies/968/glare.gif" class="smilie" alt="" />

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[zms968]

One thing that can help a lot is to coat the back of the pad where the piston contacts and the sides of the pad where they contact the caliper with a high stick lubricant or brake paste. A bad shim can also cause this.

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