My wife has a 2008 sebring crd. The clutch was going straight to the floor and losing fluid, so my mechanic replaced the master cylinder (with a second hand one, as the local dealer couldn't supply a new one). There is now no leak, but pressure is still being lost, requiring the pedal to be pumped 15-20 times to get it functioning for a short time. Has anybody had the same problem or can advise a solution?