Originally Posted by
JonathanGennick
You might fill the tube and then hold the valve area in a sink of water to see whether you spot any air leaking. Wiggle the valve around to help expose any flaws.
You mentioned tightening the little nut, which makes me wonder if in doing so you tore the valve somehow.
Possibly you just have a defective valve.
Have you gone through the 15-minutes-then-lose-pressure cycle more than once?
Yes we've done it maybe 6 times. I checked and double checked for holes or pinches. After taking it out and putting the old tubes in I held it under water and no leaks. However, it hasn't done the random pressure release now that it is outside of the tire. I'm thinking about putting a higher pressure in it and seeing if it does it but the tube expands so much more now it's not inside anything. Will it blow out before registering a pressure on the pump?