To support Eric’s input and just to be clear, Mike, may we assume that are you parking the coach and not changing anything from “Travel Mode”? Or are you parking and then leveling? I know you’ve “zeroed in” on the manifold, but…
You did mention the Dump switch didn’t function, but depending on the leveling system that may or may not be indicative here. Our HWH leveling panel has a dump button but there’s also a “dash” dump rocker switch that I use with diligence as needed in rare highway/campground road situations.
Joel