Have had this car for a couple of months now, 90k on the clock but in beautiful condition. Since having this car I have noticed a noticable squeak when braking, not all the time, and the brakes work perfectly too, no fluid loss or anything like that. At first I put it down to damp on the discs because it does come and go. The sound is one tone, not rythmic but a steady note.
However, I notice now (it was probably always there I never noticed it before) that there is a score mark of about 1mm wide on the nearside front disc outer surface, all the way round about 15mm from the edge of the disc. The other surfaces are OK, so I am assuming that there is maybe a stone chip or some foreign body between the pad and disc? The score is maybe 0.25mm deep.
I took the car to ATS today for advice, the chap said that if it was a stone or something like that then this would have worked its way out by now after two months. He said I could have a brake check done, for a charge obviously, but I said I would see how it goes.
What do you think? If this is a piece of stone or something lodged in the pad do you think it will cause further trouble or leave well alone? As I say, the brakes work extremely well - I had to stop very quickly at the lights the other day to save myself from being snapped by the camera - it stopped in a dead straight line with no noise or anything untoward from 40 to zero in a couple of seconds!
Thanks for any suggestions.
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Just to add that the brake pads have a good 8mm thickness to them so its not the rivets scraping on the disc!!
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I doubt the scored disc is causing the squeal. Is the score rusty or clean? If it's clean then either the cause is still present or the pads have worn into to score. Might be worth having a look to prevent further damage and remove any foreign matter. The squeal could be caused by old anti squeal shims and springs, dry pad backs (try copperslip on the back of the backing plate), worn caliper slides etc. My car squeals a bit but brakes very well so that's the way it's staying.
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The score is clean. You could be right in saying the pads have 'worn' into the score. Surely if there is still a foreign object embedded in the pad it would squeal all the time, which isn't the case here. Take a look at this link en.wikipedia.org/wiki/Disc_brake scroll down to brake squeal, it's an interesting read.
Thinking about this logically, the score cannot get any deeper, would you agree with that?!
I'll take another look tomorrow and in any case will keep my eye on it.
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Copperslip or approved compound on the back of the pads on the offending wheel.
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Discovered today where the squeal is coming from... the rear brakes which are drums! I was going down a hill very slowly in traffic and I applied the handbrake instead of the footbrake for a second and on came the squealing!
I am not worried about this now but goes to show how something you're convinced about is something completely different. The score in the front disc must have been there for ages and anyway, braking is perfect so I am OK with this now.
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Sounds like it might be worth checking your rear brakes shoes haven't worn right down.
IIRC, isn't there is an inspection hole plugged by a rubber bung just for this purpose ? I might be confusing my old Focus with the Cavalier it replaced though.
On my old 99 1.8 Focus, I found that the squealing was caused by a build-up of brake dust in the rear drums. If you're competent, it's possible to remove the rear drum/hub and stub axle in one piece, meaning that you don't have to touch the rear hub nut and it also reduces the chance of damaging the rear bearings.
There are 4 bolts that hold the stub axle onto the sub-frame/chasis and I used to remove these with a 10" breaker bar with pivoted head and the appropriate socket. The pivoted head was need, because the brake pipes can get in the way.
Once the drum/stub axle is removed, you can then carefully brush out all the dust (wear a mask) and apply copperslip/grease carefully to the correct points. I also applied a small amount of copperslip to the springs, which helped stop the handbrake spring creaking.
It is important that the 4 stub axle bolts are done back up to the correct torque, so only tackle this if you've got the right tools to hand and are competent at doing more demanding jobs.
Disclaimer - the above is just a summary from a DIYer to let you know roughly what's involved, so follow at your own risk ! If you want to have a go, I'd suggest getting hold of a Haynes Manual and asking back here for more advice.
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Thanks mikej for the advice. I have a Haynes manual for the car and you are correct in saying that there is an inspection hole in the drum. I believe the wheel has to be taken off to access the hole, so I may take a look when I have time. I wouldn't be confident in removing the drum etc.
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