My 89 coupe with 132,000 trouble free driving miles has developed a rattling noise eminating from both the left and right calipers and rotors being loose. Has anyone seen this condition before and/or might know what the cause would be. What puzzels me is that the exact same condition exists on both sides of the car. Thanks for the help.
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Re: C4--89 front brake calipers/rotors both loose
Rick------
I don't see how the rotors can be loose if the wheel lug nuts are properly torqued. The lug nuts are what retains the rotors, which are a "hat" type rotor, to the front hubs.
As far as the calipers go, the only way that I can see for the complete caliper assembly, including the caliper bracket, to be loose is for the retaining bolts to be loose. There are 2 bolts which retain the caliper bracket to the front suspension member.
If just the caliper assembly is loose from the bracket, then the caliper retaining pins must be loose or worn. If the front brakes are near needing replacement, I'd replace the pads and the retaining pins. The pins are available under GM #10140586 for non-FE-7 cars and currently GM list for $11.20/each. A total of 4 are required.
It's also possible that the calipers, themselves, are worn or the caliper brackets are worn. If that's the case, the only way I know of to correct the problem is to replace them. The caliper assemblies are still available from GM under GM #12520229, left, and GM #12520230, right, and GM list for $197.34/each. The caliper mounting brackets are also available under GM #10181205, left, and 10181206, right, and GM list for $66.45/each.In Appreciation of John Hinckley -
Re: C4--89 front brake calipers/rotors both loose
It sure aint uncommon, I have one in the shop right now that is the same way. Sounds like its going to fall apart when hitting bumps. Joe, Should there be any anti rattle devices where the pad fits into the caliper? That is where the action is.Comment
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Re: C4--89 front brake calipers/rotors both loose
Wayne------
The 89-96 front brakes, JL-9 or J-55, use no anti-rattle springs, at all, other than those parts that are part of the pad assembly. So, it's not a question of anti-rattle springs have been left out or fallen out (that would be too simple, anyway).
One other thing occurs to me: with GM brake pad kits there are sometimes TWO sets of pad pins provided. One set is for standard JL-9 brakes; the other is for J-55. The J-55 are a little longer. It's possible that someone used the wrong set of pad pins at some earlier brake replacement. Delco aftermarket-type pad kits and most other aftermarket kits usually do not contain the pad pins, though.
So, this might be a possibility. Also, there are to be "e-clips" on the end of the pad pins.In Appreciation of John HinckleyComment
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Re: C4--89 front brake calipers/rotors both loose
Joe and Wayne.....Thanks for the help. That's exactly what mine sounds like.....a rattling noise when going over bumps. Wayne, are you able to move the whole rotor...mine are both loose. Joe, I thought of the wrong pins but they seem to be tight.....it's the whole assembly on BOTH sides that seems to be rattling.Comment
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Re: C4--89 front brake calipers/rotors both loose
The rotor would only be loose if the wheel is off. But,this one is exactly the same. The caliper is loose.Comment
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Re: C4--89 front brake calipers/rotors both loose
Rick------
When you say the "whole assembly" is loose, are you talking about the caliper assembly WITH the attaching bracket or do you mean that the caliper assembly is loose, but the bracket which attaches it to the front suspension is tight?
When you say the rotors are loose, do you mean that they are loose with the wheels bolted on or are you talking about loosemenss of the rotors with the front wheels OFF the car? With the wheels off, the rotors may very well be loose since the only thing holding them is the caliper and the little panel nuts which may or may not still reside on the wheel studs. Either way, the rotors can appear loose. They will be very tight once the wheels and lug nuts are installed, though.In Appreciation of John HinckleyComment
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Re: C4--89 front brake calipers/rotors both loose
You guys are great.......I'm understanding more now thanks to your helpful information. The rotors are loose with the wheels off....and now I understand why. This is what had me concerned most. Thanks Joe. The claipers are rattling on the rotors. Wayne, can you advise what you will do to correct the car you are working on......thanks again for your help with this.Comment
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Re: C4--89 front brake calipers/rotors both loose
Rick------
I would say that if the calipers are "rattling" on the rotors, but the caliper brackets are tight, then the problem almost has to be either the pad retaining pins or wear in the brackets.
If I recall correctly, there is a common problem with caliper bracket wear for earlier C3's. These use a different design caliper than the 89-96. However, the problem may plague later models, as well.In Appreciation of John HinckleyComment
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