What does this mean? You don't need to pump the brakes. You should have a fairly stiff pedal all the time, even with engine off. Is there air in the system?
You can test the booster by itself. Hook it to a vacuum source, like your engine running or even another car's intake vacuum. As you push in the pedal rod, the output rod should move with very little resistance. The only force needed is to overcome the weak spring on the booster's inlet valve. You need to adust the tip on the output rod so it just barely touches the MC piston, i.e. minimal initial displacement but no "lost motion" gap. You can feel for that as you bolt the MC up.
