10-Minute Tech: No-Stick Drain Valves

Dump Valve
Illustration by William Tipton

Even with regular use of expensive drain-valve lubricants that are poured in tanks, I’ve struggled for years to operate sticky dump valves. Removing and lubricating at least the black-water valve once a year, and sometimes even replacing valves, was just a temporary fix. Then I came up with a simple and very effective solution: 1) With the valve closed, drill a small hole on the handle end of the valve. 2) Insert the strawlike nozzle that is typically supplied with spray lubricants into the hole and fill the cavity behind the valve slide gate with the lubricant. 3) Operate the valve several times to be sure to distribute the lubricant, which will make the valve easy to open and close. 4) Seal the hole with a small screw. 5) After a number of uses, when you notice that operating the valve takes more effort again, relubricate. I use white lithium grease or a silicone lubricant.

I wish I had come up with this idea 25 years ago! I can tell you from firsthand experience that it is not fun to lie down under the trailer at a dump station and remove a firmly stuck valve when your RV’s black tank is full.

Ralph Clark, Albuquerque | New Mexico




  1. The newer hoses for LP tanks have the large nut on the connecting hose that attaches to the tank valve. After filling, sometimes a bubble check will show that there is a leak at the connection, and tightening the nut will not stop it. The tank valve has a neoprene seal inside that old tanks did not have. I found that wetting a finger in brake fluid and wiping the seal will soften it and cure the problem..

  2. Brilliant! Just be careful with the drill and choose a screw before you drill. Saves a trip to the store to buy the correct screw you thought you had. Lol. Silicon works well. Haven’t tried white lithium. Thanks for this great simple mod!


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