Before your rebuild the whole thing, pinpoint the source of the problem. If the motor does not run, it could be the motor or the pressure switch. If the motor runs all the time and blows the fuse, it's probably the pressure switch. If the motor cycles too frequently (like every brake apply) and the BRAKE light flickers, it's probably the accumulator. All those parts can still be bought new (the accumulators are generic repros though). Most of the problems with the Powermaster seem to be these external parts, not the inner seals and stuff.