slow filling rear air bags

[dbosburn]

1997 American dream on Spartan Mountain Master chassis. I recently replaced all ride height valves and everything worked perfectly for about 6 months. In the past few weeks I have noticed that the rear air bags are taking much longer than normal to raise the coach. It takes them about 2 1\2 minutes longer to fill than the front. I have checked the lines and valves for leaks and found none. The rear ride height valve controls a relay valve that in turn fills the tank that supplies the rear bags. I have called Fleetwood, Spartan and so far three of the local Spartan service centers. No one can offer any help or even identify the manufacturer or part number for the relay valve. I would really appreciate hearing from anyone that may have had a similar experience and learn how they corrected it.
dbosburn@gmail.com