After last Friday's HPDE, I noticed an odd sound coming from the front brakes on the way home when I hit them. When I got home, I could see both front rotors were scored pretty badly. I had brand new Hawk HPS pads on that were only a week old, and the brakes felt/performed fine at the track that day.

Took it into the shop, and it turns out that I burned up the caliper piston seals on the front from heat!! The fluid was getting by the seals and would not let the piston fully release when I came off the pedal. These calipers have been through 6 track days, and 17,000 miles of easy street driving.

Has anyone else had this happen from track use?

 

I don't own an A4, so I don't know. But I know all about boiling brake fluid at the track. One thing I would suggest is switching your pads. HPS's are not really up to tough track duty. If you are roasting seals, you are well above their heat range. I run the HP+ pads which are better, but we would probably both be better off buying real race pads and just using them on track days. Also, look for titanium shims. They block the heat from soaking from the pads into the pistons and brake fluid. I bought mine here: http://takspeed.com/tispeed/ You can read what they do, but they don't list shims for the A4. Maybe somebody else has them though. Good luck!

 

Dot 5 or higher brake fluid, Motul has some pretty good stuff on 034 or RPIs site.
In addition to what Z06 said, red stuff pads have been pretty good for track days. Not really that great when cold, but excellent when hot.
Sounds like maybe its time for a few upgrades. Try some newer rotors maybe, too?
Take a infrared thermometer with you. See what your temps look like.

 

I'm not trying to get into it with you, but "dot 5 or higher" should be clarified. DOT 5 is a silicon fluid and cannot be mixed with the DOT4 that came in the A4. You can stay with DOT4 and use a high performance fluid like the DOT4 ATE racing blue fluid and be just fine. You could also completely flush the system and go with a DOT5 fluid, but you risk some capatibility problems that have been reported like swelling seals. Also, once a system is converted to DOT5,it is extremely difficult to go back as the silicon fluid is difficult to get completely out. The best option is probably what you were trying to say. That being a high performance DOT5.1 fluid like Motul's.5.1s are NOT silicon based and are campatable with DOT 4 fluid, (but not DOT5) yet have the higher boiling points. I just think it's important to understand what all the DOT numbers mean and what the implications of them are.

 

Yeah, dot 5 or higher. I will be honest, I wasnt sure the differences between 5 and 5.1. I know, like you mentioned, the Motul is compatable with 4.
I would completely flush the system anyhow, and run 5.1 it is a really nice upgrade. Something else are some braided steel brake lines. You wouldnt beleive the awesome difference.