[Burlyman]

I can say that on mine I had a faulty transmission modulator which was allowing air to blow past the seal and into the transmission fluid. I only found it when I was under the coach and heard gurgling in the trans pan. Part was $130 and is supposed to be replaced at every transmission fluid change. Compressor went from running every 30 min to over 4 hours

Fascinating... This is something that I would have never suspected.. I guess I will listen for some gurgling then.  Thanks for the info!