11-28-2023, 05:01 AM
Rick being a compressor I would bet reed valve but don't hold me to it as I have never had one apart. The moan you are hearing might be from one of those valves leaking by but I would think there would be a check valve in there someplace. You can hear this with your ears?
1999 45' #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon