Ok I have been havin this problem for a while i searched and couldnt seem to find anyone with a similar problem. Ok basically at auto cross i would be braking and the more i used the brakes the more pressure i built up and they would stay partialy enguaged for some reason. Also seems when i am at a high rpm the brake peadle gets very firm and then gets softer with the rpm drop. Any ideas guys i have a feeling its electronic cuz it sometimes just let loose.

 

how are you determining the brakes are staying partialy engaged? which wheel/s? the pedal feel could be caused by a leaky booster or booster vac source check valve.

 

Well it is so bad when i try to just coast it will stop and is actually hard to get going i have to rev it up, so i can get it moving cuz the brakes are on that hard. I dont know how i would go about figurin out which brakes are engauged. I will double check that my break booster lines are not leaking.

 

Sounds more like the pistons on your calipers are a little seized or worn and not retracting. That would cause the pad to drag and not release.

Not sure what to say about the pedal feel since I'm sure its being affected/disguised by the problem with the caliper(s).

There are 2 vac lines for the brake booster. One right near the reservoir and goes to a pipe on the firewall. The other on the passenger side of the motor from the pipe on the firewall to the UIM. Ray sells those for $20 or so and its worth replacing if you are having some pedal issues.

 

when the car is dragging jack up each side just enough to clear the wheels and see if they spin free.

 

Is your brake resivour over filled? If it is over filled when the brake system is cold, then you add heat by driving hard (autocross), the fluid will expand and have no where to expand into. That will cause that added pressure to be applied to the calipers.

 

Might just be me but I dont think the plastic cap on the reservoir has enough holding force to do that.

 

Maybe not, but my friend just swapped his '68 chev pick up to 4 wheel disks, and he had this exact problem I described. Granted his resivour had a pretty HD steel cap. I would still check this as it is free and easy to do.

 

all my booster hoses are brand new. I think it is probly the fact that my brakes are old as hell these days. I know my rear brakes are partialy seized, so im sure that the fronts are in the same shape. I planned on rebuilding them this winter but i have one more autocross and im done. Oh and my fluid is good not to hight not to low. I supose i will figure it out this winter...