Quote: (Originally Posted by
Mark Chase)

Yes i have isolated the gas supply. Looking at it there apears to be no 0 ring on the barrel. Its just a tolerance seel. My one failes compleatly in under a second. It might as well be open
With the bov in my mouth the unit hold neg no problem so its definiatly sucking in through the mouth piece only.
ATB
Mark Chase
Mine is just the same. I just set the unit up for diving and it holds neg when I keep it in my mouth.
If you bail it will not let any water in because you don`t have a neg. pressure in the loop. And water is tenser than gas so it needs a bigger hole to go through.