Thanks for all your suggestions.
My tank has a metal nipple. A brass fitting attaches to that and a brass female end attaches to that. The hose is plastic and is crimped to the brass female end. Very old school.
The crimp is solid, the female is tight to the brass elbow fitting, and that's as far as I've gotten with my exploration. The cardboard and insulation around the tank was all wet, and I couldn't really assess the metal nipple at the tank. Lots of calcium type buildup around that nipple as well. I will do more exploring tomorrow. It's a very tight squeeze under the coach, with little wiggle room to play with tools....
