Z32 Brake Booster question

[skylindrftr]

I bought a what I was told was a z32 brake booster from a member on here and it turned out that the studs did not go far enough through the firewall to get nuts on them (some of them). So I went to the junkyard and tried to find one with the same model number M215T. I found an automatic equipped z32 300zx with a vg30de luckily with it's brake booster still on it. I pulled it off, but there are some issues/questions:

1. Is there anything different about this brake boost/will it work well with a full z32 brakes swap (30mm iron, 17/16 mc etc)? on the top of it there is a yellow label that reads 4WAS. I thought this mean 4 wheel steering or something but I checked and found no hicas bar. The studs on this one are longer and I can actually use it.

2. The piston rod seems to move freely, I am not sure it is supposed to do this. It can be moved all around with just your hand and does not sink back into place like the other brake booster that I have. Can it still work or be repaired or did I just waste 20 bucks?

Thanks

[GSXRJJordan]

Sounds like the diaphragm is ripped if it doesn't "spring back", probably wasted $20.

Weird that the studs weren't long enough on the first one though.

Why do you want a Z32 booster so bad? You having clearance issues?

[projectRDM]

The Z32 booster is even larger so it makes no sense to use it if there's clearance issues, especially when there's no benefit besides slightly more vacuum area.

[skylindrftr]

I was using it because the of issues with pedal effort (too much). I guess that one is junk, got to find another eh?