ThetfordRV Drain Valve Lubricant 15843, 24 oz. Bottle (Quantity 5)

I like how easy it is to pull the lever to empty my grey/black water tank. Before using this product it was really hard to pull.I love the guy who invented this stuff!

All good

I use it to lubricate the dump valves in the holding tanks.

Bought this because our black valve was starting to stick. Made the mistake of using in both our black and gray tanks at the same time. Didn’t have any noticeable effect on the smoothness of either valve, but the tank sensors on both won’t go below 1/3 now, even when the tanks are empty (and in the case of black: flushed). We never had a problem with the sensors in either tank until using this product. We think it has coated the tank wall in the other side of the sensor (ours are externally mounted), causing them to mis-read.