JET FX,
I am going to keep your idea in my pocket and use it some day to find a leak. It is a daunting task to look for a leak in a plane with a mile of tubing a fittings going in and out of everywhere. I spent the better part of an afternoon looking for a slow leak in my CARF Mig-15 and it ended up being both air guages which were staring right at me the whole time...ugh.

V..