I was at a driver's school at Blackhawk Farms this weekend and after my last session, I noticed a grinding sound from my rear brakes. Not only had I run out of rear pad, the inside pad on the right and left had warped and melted into/onto the pistons. I had to pull the pistons out of the calipers in order to chisel/pry the pads from them. The backing plates left some metal behind on the pistons and I'm trying to figure out a good way to remove it. I thought of using a dremel to remove as much as I could without doing too much damage to the piston itself but I'd love to hear from one of the forum's resident experts. Does anyone have a better suggestion for removing the metal? Do I even need to bother?

 

I am not an expert but I would think you would want to remove it to made the surface of the piston even so it will apply even pressure on the pad.

With the piston out go to any shop and just kiss it with a grinder to make the surface flat and remove as much as you can.

Then when you go back to the track remove or cut the shield around the rotor on the rear brakes.

This is how mine looked like after and event. They didn't melt but did start to warp. You really have to keep an eye on that rear inside pad on both sides, they get the worst beating. The top are rear pads and the bottom are front pads with right ones being inside pads. You can see that the inside pads get worse mainly because of the heat and they start to warp and only applying brake with the middle of the pad where the piston hits and so if you look at the side of the pad you think you still have pad left but the middle is gone.

 

Stock Z brakes (non-Brembo) will go up in smoke on a track. I did the same thing, as have others. Once you get the pistons cleaned up, there are some other things to do:

1. Cut off the rear dust shields.
2. Get better pads (Carbotech Panther+, Cobalt, etc).
3. Flush with better fluid (ATE Blue, Motul, etc)
4. Turn off TCD/VDC during track days.

I've heard Blackhawk (brakehawk) is tough on brakes. Good luck.

 

Quick question, did you apply your emergeny brake when you got back into the pits after your session. If so the massive heat gets trapped between the pads and rotor and bingo your done !

 

The parking brake does not use the brake pads, it uses pads on the inside diameter of the rotor. But either way you shouldn't apply them as they will warp the rotor.

 

I was running Motul 600 fluid Carbotech XP-9 pads and I think the high coefficient of friction was what generated the heat and allowed the backing plates to warp. I'm definently going to be removing the dust shields before my next event and I'll be switching to a pad with a lower coefficient of friciton to try and generate less heat. I may try to set up some ducting as well. Can anyone recommend a good source for stock rear rotors? Mine are pretty chewed up.

BTW I was running XP-9's front as welland ended up with bad pad deposits. I'll be switching to some Pagid Orange pads for my next track day. And there was no parking brake used at all for the weekend.

 

I used Panther XP's in front and Panther + in rear and worked pretty well. And you like you said they leave some deposits that you shake like you have warped rotors, I used some sand paper to lightly go over the rotors when I was done and switched back to street pads.

 

I hope you meant to say you used "garnet" paper. Ordinary sandpaper has aluminum oxide which reacts with the iron under heat and can cause changes to the structure of the rotor. If you're going to use an abrasive paper, make sure it's garnet paper.

A rotor hone on the end of a drill is faster and requires less elbow grease than garnet paper.

An even better solution is to use a track pad that doesn't "poop" all over your rotors!