Update.

Last Thursday I received the electronic stethoscope from Truk in the mail. I did not have time to use it Thursday night, and Friday I took the coach on a short trip to get a bad valve stem replaced on a tire. When I got home, I put the bus up Jon's stands and built air pressure up until the air dyer spit. Then shut the bus down. So I planned on spending Saturday morning under the bus looking for my air leak. Well, it is now Thursday and it has not lost a single pound of air since last Friday! With no leak, testing never happened. So, I am reluctant to send Truck his stethoscope back, knowing as soon as I do, the leak will reappear.

On a more serious note, what should I suspect now? I am sure the leak will reappear at some point. I am thinking a Norgren valve, maybe a spool valve did not close in the right position? Any suggestions of the most likely place to look the next time the leak appears? I really hate these types of problems.