Originally posted by JOHNSC16V
if the master
cylinder is at fault, it should be leaking right? and also
cause some pulse while you brake...abs
Master cylinders would not typically leak externally when they fail, and there is no reason to expect any ABS pulsing.
A good indicator that your master is failing would be to press on the brake pedal for a while and find that it slowly loses pressure until the pedal hits the floor.
Water in the system would only be evident if there was fading under braking load [boiling], suchas repeated stops, or a downhill grade.
Air in the system would result in spongyness under all conditions, but is unlikely unless you ran out of fluid.
Having to push very hard to stop would indicate a brake booster failure. This symptom can be intermittent.
$375 is not outlandish for a Master. That's like 3 hours of labor.