Elliot, We are finally home and I can get back on the computer. Yes, by all means swap stuff around to isolate the problem. Anytime you have two or more parts and one of them is in a system that doesn't work switching parts around helps you find out which parts are OK by process of elimination, or which are bad.

The reason some coaches have four solenoids is because over the years both Prevost and the converters have made numerous running updates and changes to the suspension system. Hector's program that shows the workings of a system is generic, but the operating logic is correct, while the specifics are going to vary from model year to model year and converter to converter.

For anyone to have a perfect suspension system the only way to be assured of that is to actually ignore the operating logic and rebuild or replace every component after carefully bench testing all parts for leaks or proper operation. To repair the system, use the program Hector created as a guide to isolate only those parts that are actually associated with the defective part of the total system.