My former camper, a FR Grand Surveyor, had those cable pull/push thingy's. For those of you who remember push type lawn mowers with the throttle mounted on the handles these cables are much like those, an outer housing that looks much like a tight wound spring with a solid wire cable in the housing. After a few times fighting the handles to open/close the grey and black water valves I just decided to find the problem and fix it, or totally destroy something. This unit also had the enclosed underbelly with some type of aluminum paneling. I had to remove three of these panels to see everything and to get to the actual valves which were mounted on to the tanks. The cables must have been six feet long and the distance from the handles to the valves may have been 30" or so. Each time I would try to move the handle either way the cable housing would just flex. I cut the cable housing so they would be straight, then cut the actual cable to fit. I also made and installed one brace on each cable housing to help hold in in a straight line. After that the valves worked much better.