Vacationer 04,
I had the same setup you have in my rv and they were cable operated and the valves were located in a very difficult to reach area under the vehicle. After years of fighting with the valves, I relocated them to an accessible area at the outer edge of my vehicle and eliminated the cables, which I've decided were really not the source of my problems with the valves. What the problem was, was the lack of access to the valves for periodic maintenance like cleaning the sealing surfaces and lubricating the valves. Made the modification two years ago and am glad I did and wished I'd done it sooner. My latest mod is the addition of an electrically operated valve for the gray water line and I love it. Might do the same for the black water valve also.
