I have a 2011 Itasca Cambria 30C with Michelin tires and run mine at 50 psi. It really depends on how you load it. Experiment with it. The other thing is mine are hard to set accurately, the bags are small and it only takes a short burst to air th...
I don't pretend to be a mechanic but your problem sounds like something we experienced a year ago with only 22,000 miles on the odometer. To make a long story short the dealer ran diagnostics and did not find anything. They thought it was fuel pump ...
I had Borg Dually Valves installed a couple of years ago on the rear duals and its been great. It costs about $20 per tire to install them and I think the valves were about $120. I would do it again in a minute.