posted August 23, 2005 07:19 AM
I've said this before in other posts...
We had 2 problems on our 4-bar car that caused the same symptoms:
1. The bottom bar was hitting the caliper and crushing the bleeder which was causing the pads to push away from the rotor when the car was up on the bars.
2. The brake line on the left-rear was too short and every time the car rocked over hard in the turns, it would "pull" on the caliper causing the pads to pull away from the rotor.
In both cases, the driver would have to pump the brakes once before he had any pedal.
If your brake lines attach to the frame instead of following the rear end, I would check to see if they are too short. If the car rocks over harder in one turn than the other (like on an egg-shaped track), then it could be the brake line deal.
In our case, the brake line was steel-braided...I doubt this would happen with a nylon line...it would just break.)
Just some more things to check...