Recently, I noticed that the air system purge (spitting) was going off every 5 seconds of so. As I always try to be aware of any new sounds as I drive, I knew that something was wrong - even though the air gauges indicated normal operation.
Prior to my taking the coach in for repair, Gene Hammelman correctly diagnosed the problem as a bad Differential Feedback Check Valve. The replacement part is MidlandHaldex DQ6037, and it costs about $35.
However, there are possible other problems if you are purging too often, and the cause could be a bad coalescing filter. In any event, it is something that should be checked immediately to avoid costly repairs.
The DISCOVERY OWNERS ASSOCIATION, INC, was formed to promote the sharing of information and the camraderie of fellow Discovery motorhome owners. Membership in the club is limited to owners of Fleetwood Discovery motorhomes.