p-30 4w disk. Replaced rear lines and all new front and rear hoses 2 months ago. removed all pistons from calipers. bore and pistons in great shape. lubed sliders. after bleeding brakes still not what I would like (little soft, pumping brakes does not improve). Installed new master cyl. yesterday, now have good solid pedal. Too good, front brakes will not release. Made it a mile down the road and both front wheels are locked up. open one bleader and both are free. pump brakes hard and thier still free.Rear disk not hot at all. Head back to the house and they start dragging again. open bleader and free again.Defective M.C.? any suggestions.

Doorman

Next time this happens, unscrew the connection for the front brakes at the master cylinder. If that releases the brakes, the master cylinder is the problem.

The master cylinder needs to be adjusted so that it retracts completely.

Sounds like the rod that pushes in the master cly. piston has no end play, make sure that it has alittle space (32 to 16th) between the end of rod and masters piston. If you still have your old one compare the ends of piston and measure the depth of the hole where the rod enters.

Hope this helps you out.