So I was shooting my Gen 1 Terminator the other day... It was working fine, then after a couple mags something failed and the air tank almost flew right off the gun. I unscrewed the valve from the air tank and the tiny o-ring was sitting sideways, I reset it and tightened the screw. I put everything back together but it won't take any air, it's still leaking from the flat head screw next to the trigger port. The o-ring for the flat head had a knick in it, I replaced it with the closest sized I had but the leak persists. Does anyone know the size of the o-ring by chance? Or any ideas if it's something else? I checked the valve pin and that still looks good.