[Blackbirdws6]

If the piston for the slave is not able to break the plastic, then you have a hydraulic issue. It should snap easily on the first press of the clutch after the slave was replaced and bled completely. Pumping the slave by hand is the right method but you need to make sure all of the bubbles are out of it. Your hand will likely start to hurt once the pressure builds in the slave. If it was easy to press the rod back in each time, again, you have a hydraulic issue which could mean either you need to bleed it more or your master may be toast.