How do you install an expansion chamber?

[Jay]

I own a piranha BL and just recently bought an expansion chamber. When I try to install it, I hear CO2 leaking from the barrel. What the hell do I do?

[TLplus84]

when you hear Co2 leaking down the barrel, it's usually the cup seal that's messed up. Try switching Cup seals.

[Richy_C]

cock the gun b4 u gas it up

[antiramie]

Or you might be low on co2. When ur low u sometimes hear the gas coming out of the barrel.

[DraXsuS]

I had the same problem and i did what Richy told