[qcj]

Just got back from a trip yesterday and on the way back, I noticed that the supply air tank gauge would drop to 90 lbs and immediately go to 115 lbs. then drop back to 90 lbs. in a period of about a minute. I ask my wife, which can hear better than I, to walk around the coach when we got home and coach in storage and engine off to see if she could hear any air leaks. As fast as it was going down it should be heard. She or I could not hear anything, and the gauge did not move. My 110 volt compressor cuts on about every hour and a half. How long it has been doing this I don't know, because I usually just glance down at the gauges then back to road. The brake gauge is working as it should. Whats going on here?