Forum Discussion

brulaz's avatar
brulaz
Explorer
Mar 23, 2014

Drain Valve Lube

I used Silicone spray on the valves in the old trailer to keep the seals from sticking. They were readily accessible.

The new trailer has them stuck way up in the covered "basement". IIRC somebody here has managed to stick tubes up to the valves and use compressed air to force Silicone lube up onto the valves via the tubes.

But is anybody here using Thetford Drain Valve Lube? Does it work? And how often do you use it?
  • oxygen wrote:

    Not wanting to go outside this morning and check the valve, due to snow and cold, do you not need to open the valve cover or can you spray it into the opening ,the rod used to open the valve, the rod fits into?


    I did this after cleaning and flushing the tanks thoroughly. Afterwards I left the valve open, with the valve blade pulled all the way back, and wiped down and dried the rubber O-rings that the blade slides through. Then I sprayed silicone on both the inside and ouside rubber O-rings and closed the valve/blade.

    If the the valves are accessible, it's also easy to disassemble the valves (there's only 4 ? bolts) and remove the O-rings for cleaning and spraying with silicone.


    But I think you are referring to where the shaft runs into the valve. There's probably another small O-ring in there, and yes, I would spray the metal shaft with silicone and work it in and out several times to get the silicone down into the shaft O-ring in the valve. This shaft O-ring cannot be removed from the housing, AFAIK.

    I had one shaft O-ring get totally gummed up once and no amount of lube would fix it. So a whole new valve was required. I suspect it was sand and road grime that got in there. With the new trailer, I'm hoping that this will not happen as the whole valve is protected in the covered "basement", and I doubt that any lube dumped in the drains will get to that shaft O-ring and keep it lubricated. We'll see ...
  • Yes that's we're talking about. My old trailer had the valves at the end of the drains, so I could easily spray the rubber O-rings with silicone.


    Not wanting to go outside this morning and check the valve, due to snow and cold, do you not need to open the valve cover or can you spray it into the opening ,the rod used to open the valve, the rod fits into?
  • Yes that's we're talking about. My old trailer had the valves at the end of the drains, so I could easily spray the rubber O-rings with silicone. The new one has the valves protected up in the covered "basement" of the trailer.

    And yes, you just dump the oil or Thetford Drain Lube into the toilet or sink. The sinks have a trap underneath, so you will want to put in enough to overflow the trap and get down to the tank.
  • Are we talking about the valve one pulls open to empty the gray/bIlack tanks? Is the oil added into the tank from the sink/toilet outlet? From the outside, the valve is not exposed, so not sure how one would add it from outside.
  • Thanks John.

    If my valves start giving me trouble even with this Thetford Drain Valve Lube, I'll be ripping the bottom off and doing something like what you did. Hopefully not for a few years though ...
  • brulaz wrote:


    The new trailer has them stuck way up in the covered "basement". IIRC somebody here has managed to stick tubes up to the valves and use compressed air to force Silicone lube up onto the valves via the tubes.


    I am one of the compressed air and silicone guys.

    For the gray tank buried up under the cover and around 3, 90's, I added a remote blow tube.

    Drilled and taped the 1st elbow to screw in a fitting to hold the 3/8 tube


    Routed the tube down to the dump pipe connection outside the cover.


    Then drilled and taped again in just before the dump cap.


    Pop the hose, squirt in the silicone and blow it up to the valve




    In the black tank, straight up the dump pipe, I have a length of blow tube, slide it up the pipe, add silicone and blow it out to the valve. Works good. Do it about 2 to 3 times a year


    Hope this helps

    John
  • I had a leaky grey water valve and bought a bottle of the Thetford valve lubricant and after a couple months in storage we took it out and no more leak!
  • path1 wrote:
    OK not HI-tek don't laugh...

    Salad oil or Mazola oil.

    I know I didn't believe it either till I tried it. Long time Rv'er told us about this. Next time you empty tank do a good back flush to get everything out the best you can and add a jug.

    Get a bottle of valve lube stuff and feel it between your fingers then do the same with some type of vegetable oil. See if you can tell the difference.


    Well, the stuff feels and looks more like a very thick but liquid hand dish washing detergent. The bottle says something about containing a "non-ionic surfactant" so I guess that makes sense. Even smells and feels a little soapy.

    No mention of silicone or other oils. So I dunno what it's doing.

    It does say to use "routinely". Dunno if that means all-the-time, every-time you drain/clean the tanks or what. Think I'll just use the stuff before storage and every once and a while in between. If that's not good enough, I'll report back.
  • OK not HI-tek don't laugh...

    Salad oil or Mazola oil.

    I know I didn't believe it either till I tried it. Long time Rv'er told us about this. Next time you empty tank do a good back flush to get everything out the best you can and add a jug.

    Get a bottle of valve lube stuff and feel it between your fingers then do the same with some type of vegetable oil. See if you can tell the difference.
  • I use white lithium grease on mine and then work them back and forth until it is smooth again. You can find aerosol grease with a straw.