Advice please
Oulton park track day. Brakes working really well. New brembo front disks, plenty of pad material front and back. Brake fluid 1 year old.
Carrera 4 with PSM. PSM on.
About 2 hours in, Car being driven by my mate who holds a MSA A licence - much faster than me and much more aggressive on the brakes.
Sudden loss of pedal - ie pedal went nearly to bulkhead!! We had a trace of brakes with pumping pedal but only at full pedal travel. Limped to pits.
I've had brakes fade out before and it deffo wasn't like that, they were great on one corner and virtually nil on the next. The pedal just travelled++.
In paddock checked the car over, no brake fluid loss on wheels. Brake fluid level at max. Took frunk plastic off. No leaks around master cylinder, ABS pump or PSM block. Calipers were hot but equally so. No disc blueing.
Bled the front brakes. No air in fluid. Fluid crystal clear.
After 20 mins brakes could be pumped to a decent pedal. After another 10 mins brakes felt normal. Took car for gentle run on the road. Brakes all good.
Went back on track, PSM off. Did about 3x 6 lap runs with 15mins cool down inbetween. Same problem re-occurred with me driving. Car cooled for 1h, we didnt bleed anything. brakes returned to normal with a bit of pedal pumping.
Drove home. Car feels normal.
?? Master cylinder seals, all advice / ideas welcome..
Guy
Oulton park track day. Brakes working really well. New brembo front disks, plenty of pad material front and back. Brake fluid 1 year old.
Carrera 4 with PSM. PSM on.
About 2 hours in, Car being driven by my mate who holds a MSA A licence - much faster than me and much more aggressive on the brakes.
Sudden loss of pedal - ie pedal went nearly to bulkhead!! We had a trace of brakes with pumping pedal but only at full pedal travel. Limped to pits.
I've had brakes fade out before and it deffo wasn't like that, they were great on one corner and virtually nil on the next. The pedal just travelled++.
In paddock checked the car over, no brake fluid loss on wheels. Brake fluid level at max. Took frunk plastic off. No leaks around master cylinder, ABS pump or PSM block. Calipers were hot but equally so. No disc blueing.
Bled the front brakes. No air in fluid. Fluid crystal clear.
After 20 mins brakes could be pumped to a decent pedal. After another 10 mins brakes felt normal. Took car for gentle run on the road. Brakes all good.
Went back on track, PSM off. Did about 3x 6 lap runs with 15mins cool down inbetween. Same problem re-occurred with me driving. Car cooled for 1h, we didnt bleed anything. brakes returned to normal with a bit of pedal pumping.
Drove home. Car feels normal.
?? Master cylinder seals, all advice / ideas welcome..
Guy