Dump valve won't close all the way

I bought an add-on valve and installed it. Thanks for the tips on it. Didn't know they existed! :)

I also have a TC and had the same issue only with the gray tank. to change the valve would have been a huge job so the add on valve worked great.The added few inches has never been a problem.

Mine became an issue a few years back - this is what I found in my gray valve:



They are easy to disassemble, but I hear ya - age has a way of limiting your abilities. Get the grandchild out there to help - they clean up pretty well!

You can also backflush it with no tools needed.
Empty black tank, leave valve open.
Cap the outlet.
Open gray tank valve. Gray will flow backwards into black tank piping.

Many thanks for the ideas! The add-on valve sounds like a good solution. However, I'm a bit concerned about the added length. I have a 2WD truck camper and sometimes get on dirt roads with potholes.

No way would I try to change the valve. It's in a rear compartment behind PVC plumbing drain lines and I'm nearing 80. :)

I did add years ago a garden hose fitting, with a valve, to the end of the dump pipe. However, it appears to be frozen. Will try a new one as a "first fix".

I hope there's no one out there that's leaving the valve to the black tank open while camping. That's sure to cause problem.

Home toilets use 1.6 gallons of water to not only empty the bowl but to move the solids along the sewer line to the treatment plant.

RV toilets and holding tanks aren't designed to work that way. Most all good RVs have a flushing feature to blast anything left in the tank after dumping toward the dump valve. Best practice is to refill the black tank with a few gallons of water after dumping then add your chemicals (I've had the best luck with and recommend Happy Camper Treatment) before using the toilet again. If your RV doesn't have a flush feature, fill the toilet 3 times after flushing and closing the dump valve so that there's some water in the tank before using it again.

If you leave you black tank open, your solids will mound up until they prevent the toilet from draining. After that happens, you've got a lot of work to do before your tank is usable again.

ken56 wrote:
Pick up an add on valve. It will attach just like the hose and you will not need to take a shower after taking off the cap. Just use gloves and a bucket to catch the black water that has seeped past, attach the temporary valve and go. Its a temporary fix until you can repair the one that is supposed to work. Any camping supply store should have one.

My new FW had a grey tank valve that would not close all the way. I picked up an add on valve to avoid a shower when trying to dump. After using the add on valve 1 time there was enough water in the holding tank to free whatever was causing it to stick. May not be as lucky with a black tank but certainly does not hurt to try.

Since the valve is already open the tank should now be empty. Try to tilt the RV the opposite direction of the valve to move any remaining liquid away. Only 4 screws hold the valve in place and should be fairly easily accessible. Remove the valve and keep an eye on the 2 seals on each side. Remove the TP likely built up in the opening, clean and re-install. If it's anything internal (unlikely) you just buy and install a new one.

ken56 wrote:
Pick up an add on valve. It will attach just like the hose and you will not need to take a shower after taking off the cap. Just use gloves and a bucket to catch the black water that has seeped past, attach the temporary valve and go. Its a temporary fix until you can repair the one that is supposed to work. Any camping supply store should have one.

I did this for my remote valves but used a permanent valve instead. Best mod I've done in a while and only took about an hour.

Why is it always the black tank that leaks anyway?

Pick up an add on valve. It will attach just like the hose and you will not need to take a shower after taking off the cap. Just use gloves and a bucket to catch the black water that has seeped past, attach the temporary valve and go. Its a temporary fix until you can repair the one that is supposed to work. Any camping supply store should have one.