So, just for the sake of nomenclature: That's just a standard reg hose. They all turn about like that. There's not really a "service" that I'm aware of, but that O-ring does need replacing every so often. I think it's a -010 sized o-ring, and my preference is 90-duro Viton on everything I do. A dab-o-grease (I use oxylube exclusively, and just enough to coat the o-ring to "shiny") is all you'll need to get things going again.
Thank u for detailed info, I'll inspect the hose/o-ring.