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TooSexy
05-01-2007, 07:30 AM
Over the past month there has been a clicking noise coming from what I thought was the wheels. With some experimenting and labor, my friend and I narrowed the sound down to the brakes.

I have Front Stoptech 332x32mm slotted rotor/ 4 Piston Caliper on my B5 S4

Here's the symptoms:
1. Pronounced rattling/clicking sound coming from the brakes at speeds roughly 30mph and below. The slower the speed, the slower the rattle/click. At higher speeds the sound fades away.
2. After I let the car sit for a while (6 hrs or so) and I drive the car the sound is gone. It starts off softly after I have used the brakes a few times, and it gradually builds louder and more clicking (after more braking) until it peaks.
3. Below 30mph, if I apply any pressure to the brakes the noise will stop until I let off the brakes again.
4. I removed the wheel and took of the bridge on the brakes and the outside pad had slight play back and forth (but not up and down, with the retaining pin and bridge on).

Does anyone have any suggestions on how to fix this or what is causing it? Has encountered this problem before?
pms
05-01-2007, 07:38 AM
wheel bearing? just guessing.
jeremy@matrix
05-02-2007, 12:42 PM
wheel bearing? just guessing.

A wheel bearing would typically hum.

Are the pads moving in the caliper perhaps?
TooSexy
05-10-2007, 05:32 PM
I can't tell if the pads are moving. I took it to a Stoptech distributor and he said the brakes looked fine.

The sound was getting progressivly louder by the week. I had both front axles rebuilt, and now the clicking noise isn't as loud, but it's still there. What the hell is going on?
jeremy@matrix
05-10-2007, 05:39 PM
I can't tell if the pads are moving. I took it to a Stoptech distributor and he said the brakes looked fine.

The sound was getting progressivly louder by the week. I had both front axles rebuilt, and now the clicking noise isn't as loud, but it's still there. What the hell is going on?

Ship it up here, we'll figure it out. [:)]
TooSexy
05-11-2007, 08:51 AM
^ It's getting to that point. Either that, or I'll drive it until something breaks and then I'll know what it is.
jeremy@matrix
05-17-2007, 04:22 PM
You shipping it up? ;-)
diagnosticator
07-01-2007, 08:06 AM
Two piece rotors? Sounds like the rotor rings are loosening up on the hats as the rotors warm up. The rattle is the rotor ring shifting on the hat, due to loose fit when warmed up. That's why the noise stops with the brakes applied. Another clue, is the noise stops above a certain speed, because the unbalance rotor force, holds the rotor in one position, overcoming the weight of the rotor ring that causes the ring to shift around and rattle, at lower speeds.
That's my theory, and I'm sticking to it.

[drive]
diagnosticator
07-02-2007, 09:06 PM
Bump, did you ever get this resolved??
TooSexy
07-04-2007, 11:09 AM
Wow, nobody posted for so long that I forgot to check back.

Thanks for the theory diagnosticator. Whats strange is that the sound comes and goes randomly. I had my front axles rebuilt and the noise died down in terms of how loud, but it was still there. I replaced the pads with the same brand and the noise went away for a while but came back. I recently replaced the upper control arms with the CPP control arms and the sound went away for a while but now it's back.

I'm thinking my rotors might be misshapen or warped so I'm going to take them to a machine shop for an inspection. While I have them off I'll see if your theory might be the problem too.
diagnosticator
07-04-2007, 01:18 PM
Please post back when you find the cause, good luck!