Stuck waste tank valve

PAylor · February 10, 2019

Hi all,

We have spent over ten years active rving (over six months on the road a year) and had five new fifth wheels (not pre-owned). We continue to have trouble with our kitchen sink waste tank valve. We are very careful to wipe down our dishes to remove grease before we wash them. My husband has replaced the valves but we seem to end up at the same place repeatedly. I have used dishwasher detergent and hot water (a YouTube suggestion) with no luck. I know the cable from the valve to the outside has had an impact on some of the valves but ultimately the valves eventually become so clogged they won't move.

So we would love to hear about a new kind of valve or a new way of cleaning/emptying that would help us.

Thanks in advance.

Kirk W · February 10, 2019

I am amazed by the amount of trouble you have had as I can't recall ever hearing of that sort of thing. Issues with the cables is a fairly common complaint but if you can reach the valve to open it manually, that usually works. Would it be possible to leave the original valve open and add a new one near the outlet that you can operate manually?

Ray,IN · February 10, 2019

Kirk pointed out the best method to bypass the valve issue after you get it open. Do you think it's the actual valve gate or is it the cable binding/stuck? Lubricate the cable by using a cable lubrication device. If it doesn't free up the cable it actually is a stuck valve. I lean towards the cable because of your description, and prior valve replacements.

I would not try to clean all grease out of your holding tank, because you are also cleaning all waste valve lubricant away too. BTW, have you tried using waste valve liquid lubricant yet? Most of the waste valve lubricants use coconut oil, a cheap lubricant is 1C ordinary cooking-type vegetable oil poured into an empty tank.

Ronbo · February 11, 2019

This is why I installed waste valves on the pipes outside my rv. I just leave the cable operated valves open all the time. Don’t have to worry about them not working.

TXiceman · February 11, 2019

2 minutes ago, Ronbo said:

This is why I installed waste valves on the pipes outside my rv. I just leave the cable operated valves open all the time. Don’t have to worry about them not working.

I certainly hope you never leave the black valve open all of the time....major disaster.

Ken

Big5er · February 11, 2019

Ken, he added a manual that he can reach and just leaves the cable operated valves open. He still has a valve in place.

Ronbo · February 12, 2019

Thanks big5er. Yes my valves are accessible and can even be replaced if needed. I have thought about replacing them with electric valves so I can open and close them from inside. If I had problems, I would be able to easily replace them.

Pat & Pete · February 12, 2019

I've heard that the best two days an electric waste valve owner experiences are the day he gets them installed and the day he has them removed .

Just like a Corvette owner . LOL

Wrknrvr · February 13, 2019

If you replace a valve it should be lubed with pure silicone before installed.

It is available at most auto parts stores known as dielectric grease.

When the old valve is removed, clean both matting surfaces really good. Let dry, then lube both sides where the new seal mates for the valve body. Then lube the valve body where the seal is for the pipe.

Then open the valve, lube the seals on the valve itself so there is lube behind the lips of the seal. Then lube the face off the blade itself. Work it open and close to see that the lube is covering all the surface.

Maybe a touch of lube on the shaft may help. It might be wise to work the valve open and closed to work the silicone into the shaft seal. But wipe off the excess from the shaft as it may pickup dirt if exposed to the elements.

You may want to work some liquid silicone lube into the cable if it has a cable also.

Just a thought,. Vern

FL-JOE · February 13, 2019

On ‎2‎/‎10‎/‎2019 at 10:45 AM, PAylor said:

Hi all,

We have spent over ten years active rving (over six months on the road a year) and had five new fifth wheels (not pre-owned). We continue to have trouble with our kitchen sink waste tank valve. We are very careful to wipe down our dishes to remove grease before we wash them. My husband has replaced the valves but we seem to end up at the same place repeatedly. I have used dishwasher detergent and hot water (a YouTube suggestion) with no luck. I know the cable from the valve to the outside has had an impact on some of the valves but ultimately the valves eventually become so clogged they won't move.

So we would love to hear about a new kind of valve or a new way of cleaning/emptying that would help us.

Thanks in advance.

If you are continuing to have a gate valve issue and not a cable issue time and time again then look at how you are maintaining your gray tank. Even though in your description you stated "kitchen sink waste tank valve", I assume most of your 5 new fivers were plumbed with all gray water going into one gray tank thus through one gray gate valve.

As careful as you are with that kitchen sink it could be issues from shower soaps, hair, or almost anything. Do you leave the gray open most of the time or closed most of the time? Do you have a w/d? If so the washer no doubt drains into the same gray tank. My point is everyone's gray tank is going to have different "stuff".

I would first purchase a Flush King by Valterra. This will enable you to close off your black tank valve, open your gray tank valve, and back flush your gray for a good cleaning on a regular basis. Because you are back flushing from the outside up through and past the gate valve it will clean that area also.

The other thing I would start doing is when you travel between point A and B have about 10 or 15 gallons of gray water in that tank. Add one of the cleaning agents available for gray tanks. When you get set up at your next site dump that gray tank and back flush it a couple times.

When we were full timing in our fivers we pretty much followed this procedure and never had gate valve issues or gray tank odors.

Good luck.