Last weekend I finally put the truck to work towing a new to us 5th wheel home ('19 Grand Design 2930RL). Stopped at the CAT scale on the way home. Pin weight was just under 2500 lbs and I was 600 lbs under my GVWR of 11,800 lbs. I knew this would exercise the rear suspension and after disconnecting the 5th wheel, noticed that my right (passenger) air bag was firm. Suspension must have settled a bit. Just as I'd done on the drivers side, I loosened the height sensor bolts and turned it slightly. The bag released its pressure. The amount I turned it was slight and just based on the mounting holes a little larger than the mounting bolts. My theory (and again, I could be incorrect) is that these 3500 trucks should have no air in the bags when the truck is empty and full of fuel. That allows the truck to take advantage of the lighter spring pack used with this air suspension system.