Like everyone has said, keep them screwed shut. I also use the same adapter so I can use my compressor, and I leave it on the valve as you do so that if I need to pump some air into it at a gas station I can. But this takes practice and you could easily blow a tire if your not; but the gas stations around where I live have those blasted coin operated air machines and the volumn of air is not that great anyway. But also something I discovered, is that if by chance you rip your bikes pump rubber gasket while using it to repair a flat on the road and now the thing won't seal, you can simply take the seal out, turn it around for Schader use and use the converter! This is assuming of course your pump can handle both-most do.