In other words, if one pushes the pedal to the floor during the bleeding process can the MC be ruined forever?
After two good bleeds - one with pedal and one with the power bleeder - the pedal goes right to the floor.
The MC was bled and the sequence was right, prior to bleeding, of course.
I'm nearly to the point of just putting the old one back in.
Is there a neat little test for a faulty booster?
Many thanks for all of your help.