Brake squeal that will not go away

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  #1  
Old 09-04-2010, 06:08 PM
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Default Brake squeal that will not go away

I've been battling a squealing brake on my driver's side rear end. Ever since I had some work done replacing a differential bearing and the driver side axle, I have had this squeal/squeak that I cannot get rid of. This is with my Trans Am which also has traction control (if that has any bearing on any of this).

Here is what happens:
-Squeaking sound is constant even while driving and not using the brakes.
-Tempo of the squeak picks up as you apply the brake pedal
-Squeaking stops when you press the brake pedal in quite hard

I have tried:
-Lubing the back of the brake pads (worked for a few days and the noise came right back)
-Replacing the metal clips in the caliber (no affect)
-Switched the rotor from the passenger side (no affect)

Today we played around with it quite a bit. With the rear of the car raised on jackstands with the tire off and the caliper completely off:
-Rear driver side does NOT squeak when I apply gas and get the car up to 30 mph, or while braking
-Starts to squeak when I use the emergency brake
-The rear passenger side locks right up as soon as I apply the brake lightly, however the driver side does not lock up and continues to spin while squeaking
- With the rotor off, and the emergency brake applied slightly there is no squeaking

What gets me is that there is no noise when we have the caliper off the car, and the noise starts when I apply the E brake. But as soon as I reassemble everything and hit the road I get a constant squeaking. I am starting to believe it is the new axle and the connection to the hub.

I am going to be giving the guy that redid my rear end a call this week, but I just wanted to get your opinions on it.
 
  #2  
Old 09-04-2010, 06:59 PM
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if im reading right it sure sounds like something up against the axle.
 
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Old 09-04-2010, 07:04 PM
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^Yeah, but if it was the axle wouldn't it still squeak with just the rotors installed and not the brake caliper?
 
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Old 09-04-2010, 08:12 PM
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yes if its something rubbing the axle. have you tried or is it possible to use the paper towel tube trick to listen and see if you can get a better idea of the area its coming from. also might try some spray lube without the rotor to try and find it. use the little extension tip to keep the stuff in a small spot.
 
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Old 09-04-2010, 08:21 PM
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You mentioned you lubed the back of the pads. Did you use the special brake pad anti squeal material or just some plain old lubricant? Have you checked the back of the pads to see if the anti squeal shims are still there? They may have fallen out when the axle work was done. Also possible that the calipers may not be fully releasing, have you lubed the sliders?
 
  #6  
Old 09-04-2010, 08:25 PM
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I used a synthetic grease that was recommended to me at my local Napa. The back of the pads did have those thin paperlike shims on the back too. I haven't touched the caliper much other than removing it from the rotor. What is the slider Pete? What about lubing the piston in the caliper too? Thanks for the replies guys.
 
  #7  
Old 09-04-2010, 10:42 PM
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The caliper rides on 2 slide bolts that allow the caliper to move side to side and center itself about the disk. The piston/s pushes against one pad and the whole caliper moves to push the other pad against the disk. If the sliders bind the caliper cannot move freely and one pad will remain aginst the disk and cause noise. The bolts can be removed cleaned up and lubed.
The syntethic grease that NAPA gave you is not going to stop the squealing, you need purpose made RTV spray that sticks permanently to the back of the pads.
http://www.permatex.com/products/Aut...rake_Quiet.htm

http://www.airosol.com/50277.html

http://www.aa1car.com/library/2004/bf80426.htm
 

Last edited by z28pete; 09-04-2010 at 10:47 PM.
  #8  
Old 09-04-2010, 10:54 PM
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Thanks pete. I know of the bolts you are talking about. I actually swapped out the old rubber bushings they had with new ones, the caliper seems to slide alright with them. I'll try to pick up some antisqueal spray now too.

We did just notice that with the everything off, the hub (not sure of correct part name here. Assembly with the bolts for the rotor to slide onto and the lugnuts to thread onto) isn't spinning "true." When I give it gas you can see it kind of wobbling a bit side to side. We looked at the passnger side as well and it also has a bit of wobble too. I am wondering if this is normal or not.
 
  #9  
Old 09-04-2010, 11:58 PM
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That is part of the axle shaft. There is some in and out movement allowed, but it should not wobble as you described. That is usually caused by a tweaked axle shaft or a bad axle bearing.
 
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Old 09-05-2010, 12:04 AM
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I'll have to double check to see if it was just moving in and out and messing with my eyes or actually wobbling. I had all the bearings in the rear end replaced as well as the driver's side axle; so supposedly everything should be ok in ther (and I am hoping so).
 


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