Saw in my brake problem search that someone suggested "bench bleeding" the master cylinder before install.I filled my new cylinder, installed and I still can only pump up the pedal then it looses it and the pedal goes to the floor even after bleeding. That's what the old one did and I thought it was because the pits in the cylinder.I have no line leaks and the wheel cylinders are adjusted pretty close. Do I have a bad master cylinder or have I done something wrong?