Hey all,

I have noticed an intermittent grinding/scraping noise that occurs with application of brakes on my 95 M3 (I have the UUC Wilwood BBK with the Superlite calipers). I have no idea what it could be, but it seemed to start shortly after I got caught in a torrential downpour of rain, in which my car got partially submerged (luckily, my motor did not hydrolock). My best guess is that some sediment of got lodged somewhere in the system. Sometimes I hear it loudly, sometimes I dont hear it at all. My big concern is whether or not its doing harm to the rotors and/or calipers and whether not the rain I went through did any real harm to any of the parts of the BBK. Thanks.

Remove the calipers and make sure something isn't lodged between the caliper / rotor and the back plate. At Thunderhill dinanfy (sp?) had a loud scraping etc and it turned out to be a rock....

FWIW The calipers are "sealed" units... if brake fluid can't get out, water can't get in.

Yeah, I would just pull all the pads out and look around. Any idea which corner? What pads? Any problems with the bridge bolt? Pads tapered maybe with rust on them from the water scraping against the caliper?

I put the front wilwood kit on my car about a week ago and noticed a similar sound briefly. Went right away, so I dunno...

How is the quality of this kit? I am thinking about doing thus Wilwood set-up for my 323 for the next season on the track (HPDE) and auto-x.

It is a little rougher than the Stoptech in terms of fit and finish, but totally acceptable. It is a great kit, but I would strongly suggest 2 piece front rotors. The cheap price of pads and rotors (I run PFC DD fronts) is a huge plus in my opinion. The only downside I have seen is that PFC only makes the 01 without the bridge bolt design superlight pad. So either I buy them and grind them down, or have HRP do it which costs a little extra ($170 vs. $270 for Stoptech caliper pads).

check the heat shields on the rotors, they tend to get bent into the rotors and with bigger thick rotors it is easier to do.

check the heat shields on the rotors, they tend to get bent into the rotors and with bigger thick rotors it is easier to do.

I think the heat shields were probably removed to make room for the calipers. I know mine are long gone.

We trimmed a chunk out of mine. I can post pics when I get home.

You don't have to remove the heatshield. Just trim a large square section out of the top. I've been using this kit since last July without any problems. You can expect noise when you are bedding in new rotors and pads. I'd remove everything and clean/inspect to make sure nothing is stuck where it should not be.

Hate to bump this thread, but the noise is still there. Upon closer inspection, I found nothing visually that could be causing the noise. Its not the heatshields; even at full drop they dont seem to be rubbing. Went so far as to take out the bridge bolt and inspect the pads and rotors for damage or sediment. Nothing.

I know for a fact that it is coming from the drivers side front. I feel that the brake performance is compromised, as the pedal feels softer and I am getting a slight pulsation upon braking, along with the noise.

Rob L., do you possibly have any suggestions? I called your shop and they suggested it might be a wheel bearing, but I just replaced them. Maybe its a piston that is not engaging? I dunno.

how are your wheel bearings?

how are your wheel bearings?

Fine as far as know. I recently (10,000 miles ago) replaced the fronts. Never replaced the rears.

Hate to bump this thread, but the noise is still there. Upon closer inspection, I found nothing visually that could be causing the noise. Its not the heatshields; even at full drop they dont seem to be rubbing. Went so far as to take out the bridge bolt and inspect the pads and rotors for damage or sediment. Nothing.

I know for a fact that it is coming from the drivers side front. I feel that the brake performance is compromised, as the pedal feels softer and I am getting a slight pulsation upon braking, along with the noise.

Rob L., do you possibly have any suggestions? I called your shop and they suggested it might be a wheel bearing, but I just replaced them. Maybe its a piston that is not engaging? I dunno.

If you are hearing a grinding sound, there has to be something wrong. Did you inspect the inner side of the rotor? Does the wear pattern look different than the outer side?

The reason that wheel bearings are suspect in this type of situation is that a bad bearing will cause the rotor to sit out of plane with the hub. With the OE floating calipers, the looseness of the caliper can mask the problem... but with a fixed caliper such as a multi-piston BBK, the problem is exposed. Noise and excessive wear on the inner side of the rotor will be caused by the rotor being cocked and pressing against the inner side pads at all times. This will also cause a mushy pedal because the inner caliper pistons are pushed in, and there will be a space between the outer pistons and the rotor (with pad in between, of course).

It doesn't matter that the bearings were just replaced... the two times that a part is most likely to be bad is when it's old - and when it's brand new.

While that is the most likely cause, there still could be other things.

Please feel free to call me on Monday to discuss further - but please get a look at the inner rotor face ASAP.