Forum Discussion

dustycoyote's avatar
dustycoyote
Explorer
May 21, 2017

drain valve blacked and not sealing completely

ON my Carbon fifth wheel toy hauler I have 2 black tank drain valves that seem to be blocked. The valves still open and close, and will drain the tanks, but are leaking slightly when closed.

The valves don't seem to be closing completely. When I push the valve closed on each it doesn't close with a definitive stop. as I get close to being completely closed the resistance on the valve increases and when it closes it seems to feel "spongey".
The grey valves seem to maintain a consistent level of resistance right up until the valve closes completely. The black valves reach a point where the valve is still sticking out a little farther than the grey valves, and I can push them carther in but they just spring back out to that position.

I am pretty sure that some toilet paper or something has gotten impacted into the valve and is holding each one open a little.

what can I do to clean these valves out so I can close them?
  • dustycoyote's avatar
    dustycoyote
    Explorer
    May 23, 2017
    thanks for the replies.

    I would just replace the valve but my trailer has the underbelly sealed and the valve is up inside where I'd have to remove the plastic/cardboard liner to access it. I'd rather not do that.

    I think I may add the Valterra twist on valve anyway but I don't want to just leave those existing valves blocked. I want them working as well.

    I'll try Agesilaus' solution to flush the tanks and see if that helps.

    I had wondered if I could just leave those valves open and pour water in from the top (down the toilets). If I leave the end cap in place but both of the partially blocked valves open, it should fill up the pipes until those valves site under water. If I were to leave that filled up for a day or so, wouldn't the compacted toilet paper just disolve naturally? (Maybe I'll add the water softener, etc. just in case there is some more unmentionable material in the blockage as well...)

    Anyone see any reason not to try that?
  • travisc's avatar
    travisc
    Explorer
    May 21, 2017
    I had the same problem the valve is held in with four bolts undo it and clean it
  • dryfly's avatar
    dryfly
    Explorer
    May 21, 2017
    2oldman wrote:
    Your best bet is to replace them. 2nd best is to try to flush them out.


    Why would you replace a valve that simply needs to be cleaned? Several recent threads on this subject.
  • bartlettj's avatar
    bartlettj
    Explorer
    May 21, 2017
    I have the same problem, and after trying to flush/clean/lube them with limited success I just got an extension valve (Valterra T58 twist on style) to stick on the outlet. My wife and daughters have long hair and we tend to get sandy at the beach, and it hangs up in the valve seals. The extension valve doesn't stick out very far and it saves getting brown water on you when you open the cap, plus its cheap and easy to replace without having to get dirty.
  • ScottG's avatar
    ScottG
    Nomad
    May 21, 2017
    If you can drain it, blow water up backwards into the tank from the drain connection. Hopefully that will dislodge what ever is in the way.
  • agesilaus's avatar
    agesilaus
    Explorer III
    May 21, 2017
    A soak with a small bottle of Dawn detergent and a cup or two of water softener in the tank. Let it sit with a full tank 12-24 hours. Try draining, I repeated that a couple of times and freed up my valve. Easy to do before trying a replacement.
  • 2oldman's avatar
    2oldman
    Explorer II
    May 21, 2017
    Your best bet is to replace them. 2nd best is to try to flush them out.

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