[Land Yacht]

Here are some observations (not as scientific as Bill’s) about my coach and leveling. Over the past 2 years when I stop, put slides out and level either auto or manual by releasing air, and leaving in auto level, within hours to days the coach would work down to a pancake. Recently by accident, I figured out that if I manually raise the rear first then auto level, the coach is rock solid for days. Does this indicate that some valve is worn at or below ride height in the rear? If so, which one?