Brake noise
 

I was at the Chicago PCA autocross school today. Last night I put in my Hawk Blues which had at least 75% of their original thickness on them.

After one of the early runs through the slalom course I heard this horrible noise. It sounded like metal on metal. I couldn't tell where it was coming from until one of the PCA worked walked over to me (from about 50 yds away) to ask if my brakes always made so much noise. After that I listened to them every time I stopped, but I didn't hear the noise again.

On the way home however, I did hear it again when I stepped on the brakes. This was much quieter though. That first time was really pretty loud. When driving home it had to be pretty quiet (low ambient noise) for me to hear it. It didn't sound like the squeal you will sometimes hear with racing pads. Instead, it sounded like somebody had replace my pads with smooth metal. It just sounded like metal to metal rubbing, but not grinding like it would sound like with pads competely gone. I also noticed that sound when I wasn't on the brakes (when I was coasting into my garage). It seemed to be coming from both sides equally.

I haven't pulled my wheels yet to switch back to street pads, but looking with the flashlight, I can see that I still have plenty of pad left.

I can understand that pads making noise when I'm stopping, but I don't think they should be dragging while I'm off the brakes.

I've gotten a horrible brake/screeching noise after AX runs when the car has picked up a piece of gravel and it's become wedged between the rotor and the dust shield. Putting the car in reverse and backing up a few feet usually knocks the rock out.

Glazed discs.

Take #40 sandpaper and rough up the discs, then re-bed the street pads.

:cheers:

Thanks! Good to know it's something simple.

I think the loud noise was due to sand picked up.