Yeah, so were mine. And one front wheel bearing loosened on Friday. And the left front loosened at the August event. And at an event last season one of the rears was slightly loose. All were due to the bearing replacement work done by the shop not being quite perfect -- and they are a good shop. It happens, and is very easy to check for.

i wish that i could make this happen at low speed David that would make my life easier. Unfortunately it will only occur after heavy use on track.. never ever on the street

it was actually something that Dirk checked after the first time this occured on Friday - all was well

Gotcha. I was just throwing that out there as something that could be happening in addition to the main problem since it seemed the pedal normally 'drops' a little.

BTW, do you have any brake cooling other than factory scoops? Are you running stock wheels? Are the wheel spokes sufficiently open for good expose of the caliper? Have you removed the sheet metal dust shields on the insides of the rotors?

David - there is work to be done on the cooling - the ancient underbody work is tattered and the shield do need to be removed - all part of the winter improvement efforts. The nature of this issue may be heat related but we have ruled out issues at the calipers - the loss of pedal is so complete and not a fade

I suspected MC problem, but also bearings (had that happen) pushed and pulled on all wheels, no movement. Agree vacuum would just give a hard to push pedal but not a long pedal. There was no loss of fluid from reservoir or evidence of leaks. There was no fade as such as pedal did not go down slowly but just went right down, bled several times and no bubbles. Mike did a good job handling the issue, I heard "BRAKES" no panic from either of us coming into T10, he did miss the apex though!!!
Dirk

well the MC and booster and a seal kit are on their way - time will tell

old fluid stuck in ABS module? Just throwing it out there. But frequent flushing of the system might be slowly purging out the bad fluid?

Is this a two driver car? is the second driver experiencing similar issues or is it the driving style of one of the drovers? ;)

Maybe the MC is the issue. Rebuilding/replacing a potentially 15 year old component may not be a bad idea.

Did you go GT3 MC ?

did not - yet. $100 vs $550 was a no brainer given that i dont know its the right issue