Black and Gray Tank Valve Lubrication Fluids

[RKassl]

On our 2015 we have had it out about 5 to 6 time so far. During the warranty period I told my dealer at least twice that the cable controls to both black and gray are very difficult to operate. Never had any satisfaction, valves still very difficult. I even had some sizable leakage when you take the pipe cap off. Finally on this last trip, the black valve for sure failed. Anyway they had it in the shop this week and finally dropped the belly and went through both black and gray valves and I hope the cables. I think the manager said they also replaced the valve seals or what ever they are. My question is about the valve lubrication fluids that I think Thedford makes to help with valve movement. Has anyone used this tank additive on their tanks, do you think I helps? Any issues with it messing up the tank sensors? Any ideas or comments please.