Black water

[mchase1]

Today I pulled up to a spot went to hook up sewer hose... unscrewed the cap, water came shooting out. Grey and black handles were closed.. Help

[FL420]

Originally Posted by mchase1

Today I pulled up to a spot went to hook up sewer hose... unscrewed the cap, water came shooting out. Grey and black handles were closed.. Help

How much water and what color was it? Toilet valves are subject to slow leaks especially if not FULLY closed and seated in the gasket surrounding the round blade of the valve. It accumulates behind the cap up until the point there is no more room for it in the Y connecting the 1 1/2" diameter grey tank valve and the 3" diameter black tank valve. When you removed the cap the water that drained should have been equal to or less than the capacity of the piping between the valves.
I assume you quickly put the cap back on perhaps before the flow stopped on its own. If you didn't and the flow stopped on its own before a lot escaped you have a slow leak. If the water was brown and stinks with shredded toilet paper in it your black tank valve is leaking. If the water is grey, even if it stinks a bit, the grey tank valve is leaking.
If you push both handles in and one of them wasn't completely seated that valve is the source of the leak. If you can pull on a valve handle and it moves in and out fairly easily it probably has been disengaged from the valve blade and must be removed and repaired or replaced. The actuating rod has threads on both the handle end and the blade valve end.
Most any tank valve can eventually develop a slow leak. I use a 3" cap with a 3/4" garden hose connector with an attached 90° elbow and a plastic ball valve to avoid unpleasant surprises before removing the 3" cap. Any liquid will drain into the sewer hose held under the ball valve.
The next time you remove the cap have a pail or bucket under the drain to catch any liquid from a leaking valve before removing it.
[emoji40]

[Old-Biscuit]

If the dump valves were closed then one/both are leaking thru
Could be crud stuck in grove that the blade closes into...Dried TP etc

[Ron Dittmer]

Originally Posted by Old-Biscuit

If the dump valves were closed then one/both are leaking thru
Could be crud stuck in grove that the blade closes into...Dried TP etc

I agree.

Try bleaching your waste tanks, making sure to flush them well thereafter. Pour in 1/4 to 1/2 gallon of bleach and fill the tank to the top with warm water, then let soak for two hours. Not just cleaning the valves, but it cleans the tank and tank sensors. I have to do that at the end of each RVing season to prevent sewer gas due to indoor storage. My 14 year old valves don't leak and my sensors still work well.

Here is another idea. If you have enough room by the end cap, add a twist-on 3rd valve there to avoid another mess. If it leaks, what comes out will be minor. Also, the valve can be easily removed for maintenance/cleaning. Camping World sells this one for under $30, but maybe you can find it cheaper elsewhere.

[txcpl]

From your post, I assume that both waste tanks empty through one port. A temporary fix is to install a twist on waist gate valve as shown in a previous response. In reality, you need to find and correct the problem, which is a failed waste valve or valves. They are easy to change out if you can find them without taking down the underbelly of the RV. Otherwise it is more difficult. Gate valves are readily accessible at most RV part stores. Just be sure to purchase the correct size for the valve you determine needs replacing. There are you tube videos on how to do this repair. Good luck.

[Ron Dittmer]

Originally Posted by Ron Dittmer

I agree.

Try bleaching your waste tanks, making sure to flush them well thereafter. Pour in 1/4 to 1/2 gallon of bleach and fill the tank to the top with warm water, then let soak for two hours. Not just cleaning the valves, but it cleans the tank and tank sensors. I have to do that at the end of each RVing season to prevent sewer gas due to indoor storage. My 14 year old valves don't leak and my sensors still work well.

Here is another idea. If you have enough room by the end cap, add a twist-on 3rd valve there to avoid another mess. If it leaks, what comes out will be minor. Also, the valve can be easily removed for maintenance/cleaning. Camping World sells this one for under $30, but maybe you can find it cheaper elsewhere.

I forgot to include this in my previous post. During the bleach soaking process, have the end cap on and sealed, and flood both sides of both valves. Work them open and close to loosen the crud and allow the "warm" bleach solution to be more effective.

I wish I could edit older posts like in other forums. The "Edit" button disappears after an hour or so which gets me all the time.

[TandW]

Everybody needs to install the cap that has the smaller cap with hose bib. These surprises would be less so if you all did this.

[NRR]

I had a teenage neighbor open & close the black valve just for fun. The valve was in a weather protected container and operated by cable. So, there was a fair amount of stuff in the pipe. I found no joy in his humor.

[mchase1]

Thank you a lot of good advice!

[mchase1]

Thank you, I do have enough room I will go get one

[FL420]

Originally Posted by Ron Dittmer

I agree.
Here is another idea. If you have enough room by the end cap, add a twist-on 3rd valve there to avoid another mess. If it leaks, what comes out will be minor. Also, the valve can be easily removed for maintenance/cleaning. Camping World sells this one for under $30, but maybe you can find it cheaper elsewhere.

Originally Posted by mchase1

Thank you, I do have enough room I will go get one

I have had a Valterra portable waste valve for several years and use it weekly to dump my tanks directly into the sewer opening at the dump stations or into a Thetford SmartTote2 35 gallon floater toter to haul behind my Kia to the dump station. It is invaluable either way.
I use it to backflush the black tank with water from the grey tank several times while dumping. My 60 gallon grey tank sits side-by-side at the same level with my 40 gallon black tank. I dump the contents of the black tank completely through the open black valve AND the open 3rd valve. I then close the 3rd valve leaving the black tank valve open and open the grey tank valve which sends half its contents (up to 30 gallons if full) into the black tank.
When the bubbles stop rising in the top clear elbow on the 3rd valve I close the grey tank valve then open the 3rd valve observing some leftover contents of the black tank mixed with half the contents of the grey tank passing through the clear elbows on the way to the stinky slinky.
When the flow stops I close the 3rd valve, open the grey valve to send half its remaining contents (up to 15 gallons) to the black tank and do the same procedure again. If the grey tank was completely full I might do it a third time. The last thing I do is close the black tank valve, open the grey tank valve and flush the 3rd valve and stinky slinky with the remaining grey water with a dose of Dawn dish detergent in it.
I got the Valterra portable valve from Amazon.
[emoji40]