rlaifatt

This may be unrelated, but if fluid level got too low (e.g., when bleeding) and air got into the master cylinder and ABS modulator unit, that would make your brakes very spongy and bleeding will not get the air out. You have to activate your ABS a few times to get that air out, then bleed. I had that happen twice (installing ABS modulator unit). To activate ABS, find a sandy spot in a safe area, enough to lock up even one wheel, and activate ABS a few times. I was able to do it at only about 20 mph on a sandy spot at the end of my street by the curb, so it's easy.

teamking

It was funny, in this autocross I had a co-driver, and the guy running grid wasn't very experienced and wasn't getting us to the line often enough. By the time he realized his mistake, the session was almost over and I had three runs left. So, I did my last three runs in a total of about 6 minutes. In fact, I had the last two runs of the session-- I did a run, never stopped in the grid, rolled up to the line, and was immediately started again. So, if ever there was an opportunity to overheat the brakes in an autocross-- this was it.

All that said, I don't want to dismiss your opinion on this... I don't want to be driving around with a latent fault in my braking system. hmmm.

rlaifatt: Up to that point, I had never gotten low on brake fluid in the three years I've owned the car (although when bleeding the brakes after replacing the rear calipers, I did allow it to get too low during the bleeding process). I'm not sure I've engaged ABS since then, so I'll be sure to do that and bleed again.

All that said, how does this sound for a grand unifying explanation:
The brakes didn't just seize one day, never to move again. Rather, they seized, unseized, seized, unseized, in a process that got worse and worse. At some point in september, they seized for long enough to boil the fluid. During normal driving, I didn't notice it (it was subtle enough that the brakes still worked fairly well). However, during an autocross, I noticed because I was able to push the brakes to the floor without engaging ABS. I bled the brakes, fixing the *symptom* temporarily. Perhaps the piston stayed 'unseized' for a while. After a couple of months it got progressively worse. I can tell you that on the day I noticed the problem, I heard a noise coming from my rear, and could smell brakes. When I got to my destination, my rim (much less the rotor) was hot enough to boil spit.

Anyone buy that?