the spring isn't all that strong actually. I cut mine up to fabricate the booster delete plate for my car, and I could easily control the booster with my bare hands and open/close it without struggling. It's a big spring, but it isnt very heavy gauge steel
the foam seal was not quite sealing,so i trimed the old diaphram and glued it to the firewall
after i put it all together it was time to bleed the system.
the fluid was quite old
Joe, the booster is still leaking by, at the moment Im running with no booster. Brakes are great just no power assist. It has the same hiss from the booster as it had before I replaced the diaphragm. I don't like any vacuum leaks so I disconnected it.