I've been super busy since my last outing at Sebring at the end of January, but just got around to giving the car a once-over to make sure everything is still there, lol. I did notice a few things...

exhaust tips got HOT! they actually turned a light goldish color from the heat. I also notice the tips wobbled around a bit, and actually made contact with one small area of the rear bumper that surrounds the tips and melted it a little. Solution - weld an exhaust hanger to limit movement of the exhaust tip.

another thing I noticed was when I was inspecting the brakes was that the caliper is actually a slight goldish color from the heat (was pure silver before the track event) but then when looking at the caliper itself I noticed some kind of black goop running down the front part of the caliper (the area where the pad first makes contact with the rotor). I touched it and it is sticky, almost like a tar-substance. I then noticed a few small little tar/rubber balls stuck to the inside of the wheel.

Is this normal grime from running Sebring? man this stuff is nasty and is a pain the clean off... but I guess a bit got stuck to the rotor or the side of the brake pad itself and melted.

I also noticed a little bit of brake fluid that was dried up on the side of the caliper, and appeared to be running down from the bleeder. Is this normal as well, to have a little bit of brake fluid weep from the bleeder after a track day? The pedal is still firm, so no air is getting into the system. I'm thinking that the system might have been a little overfilled, and the fluid had to escape somehow... (i also noticed a little fluid came out of the top of the reservior).

 

No brake fluid leakage is normal at the caliper. Either you were really sloppy bleeding the brakes, or you have a leak.

Balls of track rubber are not uncommon to see accumulated inside the wheels and various other places, but I'm not sure that's what you're talking about on your brakes. Track rubber isn't really tar-like. Just softish rubber from race tires that gets left on the track and picked up by your tires and then shed by them in little clumps.

If whoever assembled your brakes used a lot of grease on the moving parts (caliper pins, contact points of the pads, etc), that grease could have melted and run out when the brakes got hot. Without knowing exactly how much goo we're talking about, it's hard to say.

 

yeah it must be a leak at the threads of the bleeder. only thing is, if it were a leak, wouldn't air enter the system as well when the pedal is released? I'm probably just going to replace the bleeder screws, or just buy some of that thread sealant that speed bleeder sells and coat the threads of each bleeder screw.

 

the track had new sealant put down in quite a few places a few months ago... that is most likely the tar like substance.

did you bleed the brakes during the weekend? could easily be a sloppy bleed like Loren suggested.

 

nope, last time I bled the brakes was about 4 months ago, with about 8 auto-x events done before the sebring event and had no problems there.

I actually brought this topic up on the Cadillac forums and I've had about 8 people reply that the same thing happens to them. Last night I even checked one of the bleeders to see if there was air in the system, and not a single little bubble came out, it was pure fluid, so air isnt getting into the system.

One thing I was reading is that with the calipers on these cars getting so hot due to the tremendous weight that they are having to stop, there could be a very very slight expansion in the metal, allowing a tiny bit of fluid to pass through the threads. that is why I am not seeing this leak anywhere else; daily driving or at auto-x events. Which makes since because I havent had one small drop of fluid drip down since I bled the brakes several months ago. I did turn my calipers a light gold-ish color from the heat too.

 

The air outside the sealed brake system is at ~ 14 psi. The brake pressure inside the system under braking is about 10,000 psi. It's not unreasonable to see a slight leak of fluid, but no sucking of air in just the right circumstance.

Typically, the air in a caliper that's been bled properly comes from boiling the brake fluid and releasing trapped moisture, not from air being sucked in.

 

ah, okay that makes sense. wow, i had no idea the pressure in the system got that high!

 

well its the pressure your foot presses multiplied by however much brake assist your car gives you through electronic brake assist, abs, power brakes, and the master cylinder... plus then it then goes through a tinnnnyyyyy little line. pressure is force over area so when you multiply the shit out of it and reduce the area.... yeah, it gets high. lol

 

I may have exaggerated a bit, but it's up there. Well over 1000 psi.

 

even that is a TON of pressure