On our 2015 Montana 5ver, when the black valve is closed exit pipe continues to drip. There seams to be some kind of debris in seal preventing it from completely sealing. Is there any kind of chemic...
They do make a valve that you can attach to the existing valve thus you have 2 valves in line. I carry one as a quick fix if I have a leaking valve and do not wish to try to fix the original valve on the road.