View Full Version : Dump Valve Lube

11-13-2011, 07:56 PM
Just wanted to share this tip again in case some have not tried this. As part of our winterizing process, I decided to pour vegetable oil into the gray and black water tanks and work the dump valves to lubricate them. Have done this before but had been a little over a year. I had forgotten what a difference this makes, valves work better than new! Decided to leave just a little in the tanks to sit against the valves through the winter to keep them from drying out instead of antifreeze.

11-14-2011, 10:57 AM
Last weekend, David complained, ours are really stiff and getting harder to pull open or closed. I gave him some spray lubricant to see if that helps. But he only dumps every 2 wks and the gray tank is open 24/7.

I tried to get him to buy some vegetable oil on Friday before we left for the weekend. But I couldn't remember if a gal of oil was enough for each tank.

11-14-2011, 08:14 PM
One gallon of oil is just about the right amount. For the gray, took the trap loose under the bathroom sink, emptied out the water, reconnected it and poured the vegetable oil down it. Then when done with gray valve, removed oil from trap and used it down the toilet for the black tank valve. For the black tank, just pour down the toilet. After getting the oil in the tanks, work the valves open an closed several times to work the oil into the gate seals until they slide easily. On ours, it took putting about 1/2 gallon of oil in each tank and running it through twice to get them loosened up real good. Did the gray first and then reused it for the black tank and then used fresh oil the second time through for the black. One gallon of cheap vegetable oil (fry oil) at GFS is about $4.50.