Weird Marks on my Rotor
 

Saw these weird black marks on my front driver's side rotor yesterday. They are about evenly spaced and go all the way around. This is the only one of my rotors that are like this, the other 3 are perfectly fine. Anyone know what they are and how I can get rid of them?

The brakes work perfectly fine, no vibrations or anything. The marks wouldn't wash off when I washed my wheels yesterday. I was thinking they might be pad deposits, but I wasn't sure. I'm running Carbotech XP8 pads all around.

http://i1203.photobucket.com/albums/...s/IMAG1419.jpg

They look a bit like hot spots.

Yep definately hot spots or hard spots caused by excess heat. Could cause vibration over time. You need to re-bed them.

Thanks guys, I'll try to re-bed them later tonight. :tiphat:

Have fun :driving:

I will, just gotta find the right time and place to do it. :tup:

I find it a little strange that it only happened on only one rotor and not the same one on the opposite side.

VDC at work.

:roflpuke2:

It is also possible that you have a caliper that is not retracting properly (dirty or seized piston) and is applying some additional load even when the brake isn't depressed but you would probably notice some pulling if that was the case.

I had a seized caliper on a car and it made some awful looking heat spots but they don't really seem to impact anything.

Nope, I haven't noticed any pulling. Hopefully it is just the hot spots and they'll go away after I re-bed the brakes.

Carbotech FTW

I have the exact same thing happening to my rotors right now with the hawk plus pads all around after I went to chuckwalla at 100deg few weeks back. Hot spots turning blue etc,

Our OEM rotors are not very good. I would go with something a little more durable if you are going to be running aggressive pads.

I'll be replacing the front rotors with dba 5000 2 piece, not sure yet what on the rear......... I will be running softer compound pads in the rear next time around

Don't have money to upgrade them yet so I'll stick with the OEM rotors as long as I can.

If you park the car after a track session or a hard-drive and walk away, you will get heat-soak under the pads into the rotor. At a track day. I always carry a small piece of 40mm square timber (an offcut is all that is required) to stop the car rolling away when parked on the pit apron, and every 1 or 2 minutes, push the car 2 feet and re-chock the wheel - move the vehcile enough to rotate the wheel by (say) 90 degrees and shift the pads to another segment of the rotor - this allows the whole rotor to cool more uniformly that it can otherwise.

Is also a good option to not apply the handbrake when the rear rotors are ultra hot.

RB

That's probably how it happened in the first place. Had a cruise with the mid-A gang on Saturday and pretty much drove my car hard all day and night afterwards. Didn't really allow the rotors to cool whenever I parked the car.

Good news though, re-bedded my pads and the heat spots are gone! The forum saves the day again, thanks a lot guys! :tup: :tiphat:

http://i1203.photobucket.com/albums/...s/IMAG1420.jpg

I just drive straight to the gas station to top off because of the fuel issues, and at most tracks thats a 5-10 minute drive and it cools the brakes too.