It sounds like you could have a valve leaking. I just dealt with the good folks at Lippert for a problem with my Power Gear leveling system. I strongly recommend getting in contact with their customer service department and seek their input. The tech that i worked with knew so much about my system I thought he was one of the engineers that helped design the system. He knew exactly what to look for, no runaround or guess work.
My experience with them was , they reacted fast, went out of their way to help resolve my problems and then followed up to make sure I was 100% satisfied.