Sticky Brake Pedal

[jporter]

I have a 2001 996 tt with 39K miles and it is all stock. I had an issue with my brakes over the weekend at Mid-Ohio and thought someone may know the cause. At the end of the back straight (longest straight on the track) I threshold brake with my right foot for about 3 seconds and downshift at the end of the braking using heal-toe, turn into turn 7 (right hand turn) and full acceleration through 7 into turn 8 (appropriately called Madness). When I start to left foot brake into 8 the pedal or master cylinder seems to be stuck at the top and I have to push harder to break it loose and then everything seems ok. The brakes work great on all other parts of the track.

The brakes and rotors are stock and I use Motul RBF 600 that is changed before each event and I’ve never had a problem with boiling fluid causing a soft pedal.

I would appreciate any thoughts on what could be causing the sticking pedal or master cylinder.

Jim

[Sunnyside]

Jim,

I think what you have done by left foot braking and using the throttle is use up the vacuum reserve, so the brakes were no longer servo assisted for those few seconds. That's what it sounds like anyway.

[jporter]

I think what you have done by left foot braking and using the throttle is use up the vacuum reserve, so the brakes were no longer servo assisted for those few seconds. That's what it sounds like anyway.

Thanks. That could be it as there is very little time between 7 and 8. I'll do some research on how the system works.