Rear brake groan

[bruceman07]

i recently did a complete rear brake job on my '02, (2 months ago) new rotors, good ceramic pads, new calipers, all new pins, greased the slides aĺl that good stuff....im starting to get a low speed groan, stopping at a light, backing up, etc, the car stops nice and straight and there is no wheel bearing issue that i can tell, tires are brand new michelins. is it possible i didnt set the piston caliper quite right, i did turn them in with correct tool and the nitches are in correct position to hook the tab on the pad, pads are in cirrect with the squealer on the outboard pad. is the anything out there that shows specific how far that piston is supposed to be turned in or out to contact the pad on reassembly im going to take them both all aprt again and clean and readjust, ive been driving down a lot of dirt roads lately and wondering if this is the cause since it went weeks with no noise. any ideas, it seems somewhat common for the groan in rear bonnevilles according tothe web, thx!

 

[melsg5]

Could be the dirt or the ceramic pads.
Try Brakekleen spray and see if that helps.

 

[omologato]

Hello Bruce,

Personally I don't associate "groan" noises with brakes so I wanted to ask if it's a possibility that your rear end is the culprit for this noise vs the brakes. I find a groan noise with deceleration to be something with the pinion either not properly loaded or a bad bearing etc......

Did you follow the proper bed-in process when installing the new brake components? It's a very common mistake to not bed-in the new brake parts properly upon installation. This is a process to “mate” your pads to your rotors with gradually increased heat cycles to create a thin, even film of brake pad material on the surface of your rotor. Improper bed-in process or failing to do so can cause increased brake noise and or worse is to a high degree the cause of brake "pulse" vs the common mistake that a rotor has "warped". I have installed so many brakes in my time and I rarely find a warped rotor to be the cause.

 

[melsg5]

Hello Bruce,

Personally I don't associate "groan" noises with brakes so I wanted to ask if it's a possibility that your rear end is the culprit for this noise vs the brakes. I find a groan noise with deceleration to be something with the pinion either not properly loaded or a bad bearing etc......

Did you follow the proper bed-in process when installing the new brake components? It's a very common mistake to not bed-in the new brake parts properly upon installation. This is a process to “mate” your pads to your rotors with gradually increased heat cycles to create a thin, even film of brake pad material on the surface of your rotor. Improper bed-in process or failing to do so can cause increased brake noise and or worse is to a high degree the cause of brake "pulse" vs the common mistake that a rotor has "warped". I have installed so many brakes in my time and I rarely find a warped rotor to be the cause.

2002 Bonneville is front wheel drive, no ring and pinion in back.

______________________________

 

[omologato]

2002 Bonneville is front wheel drive, no ring and pinion in back.

Wow I need to get reading glasses bad!!! I thought it said 82 Bonneville. Which now that I think about probably had only front disc and the rears were drums.

Now that I have the correct car I can be of better help instead of a hindrance.

Okay so 2002, well since there isn't much back there with a front wheel drive car it's got to be the brakes or possible wheel bearing. Although there may not be any play in the bearing they can still make a lot of noise.

Really depends on if the noise appeared only after the brake job of course. Well, unless the rear brakes where so far gone they were grinding or making noise enough to mask the wheel bearing noise and now the brakes are fixed you are hearing the wheel bearing. I'd probably just bite the bullet and take the rear brakes apart again and see if there is anything out of the ordinary that could be rubbing that would make the noise.

One more thing I can think of is that maybe they gave you the wrong pads like a louder Metallic type. Or it's possible the ceramic material is defective and louder than it should be. That's kinda the whole point of ceramic pads is the trade off between less bite for more quiet operation.