Tight dump valves

[LI-Camper]

My friend has a small class c. She has trouble opening and closing the black and gray tank valves. Is there any lubricant or suggestion to make them easier to operate? Thanks

[Cobra1]

I use silicone spray on the metal rod and pinesol - twice a year - in the tanks to aid in cleaning and it also lubricates the valve somewhat. Anyway, works for me but they will never be easy to move because of the design of the valve - it is a gate valve and has lots of friction.

[BFlinn181]

Silicone spray works on the pull rod and cable. (if so equipped) For the actual seals and moving part of the gate valve, use plumber's silicone grease.
DANCO 0.5 oz. Silicone Faucet Grease-9D00088693 at The Home Depot

When the tanks are empty, put a dab of grease on a stick or bent coat hanger to reach up the drain line and apply to the lip of the partially open valve.

[LI-Camper]

Thanks, I'll pass these suggestions on to my friend.