How Do I Go About This?
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Launching!
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From: Orange County, CA Age: 26
How Do I Go About This? I'm having some trouble with my rear brakes, the rear passenger side to be more specific. I'm getting a metal to metal noise under light braking or no braking at all. If I really punch the pedal it goes away. Going around corners makes it worse. I've changed the pads (ceramic), resurfaced the rotors, lubed all contact points in the calipers with high temp synthetic grease, with no luck. The noise went away for about 100 miles then came back, very frustrating.
My mechanic checked the e-brake, wheel hub and axle and they were all fine. I was starting to wonder what the hell was causing this
Then I started searching through some threads on CZ28.com and came across this little nugget...
I copied and pasted this post from this thread http://web.camaross.com/forums/showt...akes+squeaking
Now I am fairly convinced that this is the answer to my problem
So my question is what would be the best way of approaching this?
Would I be better off just taking it to my GM mechanic and let a professional take care of it?
Has anyone else encountered this problem or a similar problem?
Any feedback on this would be greatly appreciated
Thanks alot
Chris
My mechanic checked the e-brake, wheel hub and axle and they were all fine. I was starting to wonder what the hell was causing this
Then I started searching through some threads on CZ28.com and came across this little nugget...
I think I know what is causing your problem.
You said,...The sqealing occurs only under light braking or no braking...
Does a corner make it worse?
If so you have to shim the rear axle or the brake plates to move the caliper slightly. The caliper can rub on the disk and what you hear is a metal to metal squeal. There is a section in the GM shop manual about this.
The braking makes it stop because the force from the pads centers the caliper over the disk and nothing but the pads are rubbing.
If the noise seems to be from the rear axle, thats your problem.
Z28
You said,...The sqealing occurs only under light braking or no braking...
Does a corner make it worse?
If so you have to shim the rear axle or the brake plates to move the caliper slightly. The caliper can rub on the disk and what you hear is a metal to metal squeal. There is a section in the GM shop manual about this.
The braking makes it stop because the force from the pads centers the caliper over the disk and nothing but the pads are rubbing.
If the noise seems to be from the rear axle, thats your problem.
Z28
Now I am fairly convinced that this is the answer to my problem
So my question is what would be the best way of approaching this?
Would I be better off just taking it to my GM mechanic and let a professional take care of it?
Has anyone else encountered this problem or a similar problem?
Any feedback on this would be greatly appreciated
Thanks alot
Chris
I have the Helms manual for '99 Camaro and cannot find this problem or the mentioned proceedure in it. You can move the caliper inboard by putting a shim on the two bolts between the caliper mounting bracket and the flange on the end of the axle it bolts to. If you have access to a micrometer or good caliper, you can make some measurements and see what you have and what changes you can make. If not then simple trail and test will also work. You might try taking off the caliper and removing the pads. Then measure the distance from the rotor to the caliper mounting surface (machined) on the mounting bracket. If you have or can get a dial indicator I would also check the brake rotor for runout. Then add shims and remeasure. Shims should be available from any good auto parts store. If not call some local machine shops and see if they have anything. I would think something from 20 to 60 thousandths would be a good place to start. Once you made a change, reassemble and take for a short test drive.
TECH Fanatic
Joined: Feb 2003
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From: Columbus, OH
No need to shim the rotor or caliper. Our calipers are on sliding pins that allow the caliper to center itself on the rotor. If you have any need to shim the rotors, you real problem is one or more stuck slider pins. Pull them out of the PAB, if they look decent, regrease them with a good caliper grease. Otherwise, clean them off with brake clean, lightly sand the pins down if needed, then re-grease.
TECH Fanatic
Joined: Feb 2003
Posts: 1,586
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From: Columbus, OH
BTW, it's not a metal to metal squeal unless you have metallic brake pads. What pads are you running? It's also possible that the brake pad squeal shims (if so equipped) are deteriorating. Also, some pads simply squeal as a fact of life or even a foreign object or other troublesome spot in the pad material itself.
Teching In
Joined: Sep 2005
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I'm new to this board so hello. I have this same problem on my 94 Z28, heres what I've come up with. It is infact metal on metal, and it's not the caliper or the pads, it's the rotor face on the caliper mounting bracket, and it actually has nothing to do with the brakes. It is excessive in/out movement of the axle in the axle tube. The squeeling happens when the axle moves outward, and the face of the rotor hits the outboard part of the caliper bracket. The GM "fix" for this is shimming the bracket out so the rotor can't reach it. My problem with that is it didn't do it for 100k miles, so the real fix would be eliminating that excess slop in the axle. I haven't had the funds to dig into my rear yet, but I'm thinking it has to be worn c-clips or axles, or maybe bearings. Do c-clips come in selective sizes like shims? Do you think they could wear thin, or maybe the slot on the axle that they key into? Am I atleast on the right track here, what do you guys think?
Thread Starter
Launching!
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From: Orange County, CA Age: 26
Originally Posted by pimpmaro
BTW, it's not a metal to metal squeal unless you have metallic brake pads. What pads are you running? It's also possible that the brake pad squeal shims (if so equipped) are deteriorating. Also, some pads simply squeal as a fact of life or even a foreign object or other troublesome spot in the pad material itself.
Originally Posted by Smokin Z28
I'm new to this board so hello. I have this same problem on my 94 Z28, heres what I've come up with. It is infact metal on metal, and it's not the caliper or the pads, it's the rotor face on the caliper mounting bracket, and it actually has nothing to do with the brakes. It is excessive in/out movement of the axle in the axle tube. The squeeling happens when the axle moves outward, and the face of the rotor hits the outboard part of the caliper bracket. The GM "fix" for this is shimming the bracket out so the rotor can't reach it. My problem with that is it didn't do it for 100k miles, so the real fix would be eliminating that excess slop in the axle. I haven't had the funds to dig into my rear yet, but I'm thinking it has to be worn c-clips or axles, or maybe bearings. Do c-clips come in selective sizes like shims? Do you think they could wear thin, or maybe the slot on the axle that they key into? Am I atleast on the right track here, what do you guys think?
Just get the car in the air and find where the PAB (pad abutment bracket) is contacting the rotor and then loosen the PAB to move it over a bit, them grind the spot on the PAB that's touching. 1/16" should get the job done and be no big deal. Then loctite those PAB bolts down to 70lb or so. Or if you have a dremel and grinder with a thin cutting disc you may be able to open that gap enough wthout taking the bolts loose.
I swear, you guys sometimes over complicate things.
I swear, you guys sometimes over complicate things.
