Well, this has been interesting. My wife wrote the original threads because I had not gotten around to it. (The coach is in storage, no harm, no foul). Yes, this is our sixth coach and four were diesel pushers. We were 'full-timers' for three years in a 41' Holiday Rambler. I familiar with air brake systems and operation, I had a CDL for about a year several years ago. After I retired, I drove a school bus 'to give back to the community', (or whatever). I always do an air brake check before operating any coach and that checks out OK. I have never had this particular problem with air brakes and while I do appreciate the positive replies and those who actually answered my question, I was shocked and dismayed at some of the condescension and vitriol. (My wife also knows how to do an air brake check, but we just bought this coach and she has not driven it yet...just sayin').