Don't know if this will help you or not, but, I have a habit of manually raising the bus up to highest limit and then down to the lowest, then back to ride height at least once a month to kind of "exercise" the bus air leveling system. Sometimes more often.

Also, with the key off, I switch my level low rocker switches back and forth several times to keep any minor dust or corrosion from accumulating on the electrical contacts.

In my opinion, lack of regular use can be a significant contributor to a laundry list of problems.

Hope this helps....