I recently took apart and cadnium plated several brake power boosters. After reassembling two of them I reinstalled one a 70 chevelle. Now when I press on the brake pedal it sucks down to the floor and you have to reach down and physically pull the brake pedal back up. I swapped it with the other reassembled booster with the same result. I must have put them back together incorrectly, don't see how, they only seem to go together one way and it's all faily simplistic.
Anyone know what I'm doing wrong?
Thanks

I've not got a clue!

Accidently leave out an internal spring?

No the spring is in, the seals appear to be working.

For each booster, I bagged the internal componets prior to plating marked the appropriate booster and reassembled all the parts to the appropriate booster. Just to clarify.