Black Tank Dump Valve

On a previous trailer, using a box cutter, I cut an access opening into the Coroplast under belly panel.... replaced the valve, and resealed using the piece of Coroplast that I removed and Gorilla Tape...

tip: make sure the black tank is empty before you remove the old valve....:E

No floor cutting required - you can get something like this to add on - http://www.adventurerv.net/twist-waste-valve-p-683.html or you can buy and install a replacement. Make sure the tank is empty and as clean as you can get it before you remove the old one. And, having the right tools is a must.

I had a problem last trip, got home gave the tank multiple Dawn/Calgon soak treatments (soak at least overnight for each one) and it went away. I still wasn't sure tho and pulled the valve out and it was fine. Nice and clean tho.

Don't need to cut a piece out, just make a 3-sided flap, to make resealing easier. Even with tank empty, it's a good idea to raise the driver's side, pulling up on a plank, to keep any residual fluid away from valve.

Jerry

Can you be a bit more specific? You say the dump valve does not close completely? Does that mean the actual valve is not seating correctly, does it mean the handle is bent and won't slide any more? Does it mean you are closing it as far as you can and it's still running on you?

If closing completely, you might try getting a round shaped brush, see if you can reach the actual valve and give it a good scrubbing. You've got nothing to loose since you are considering replacing it anyway? If it's closing all the way, it's possible it just has crud on the seals. And then again, it's possible the seals could just be worn out too. But a good scrub brush on the end of a stick, swirled around the seal won't hurt anything in your situation. Try it first. See what happens.

The add on is the best way to go. My valve wasn't closing completely and allowing liquid to drain out between dumping cycle leaving only solids. Solved problem. Ron Day

Even with property functioning valves, I still recommend the termination valve! We have two grey tanks that with the termination valve I can basically use as one by leaving both grey valves open and termination closed allowing them to equalize. Comes in extremely handy, eliminates unexpected spills, and definitely stops leaky valve issues and messes.

Greene728 wrote:
Even with property functioning valves, I still recommend the termination valve! We have two grey tanks that with the termination valve I can basically use as one by leaving both grey valves open and termination closed allowing them to equalize. Comes in extremely handy, eliminates unexpected spills, and definitely stops leaky valve issues and messes.

Exactly what I did, doubled my shower time between dumps. Having the ability to cross connect the grays is awesome. That should be a built in feature.

I use a end termination valve as well too BUT I am surprised nobody has mentioned that the valve will not close all the way is because toilet tissue got stuck in the knife valve and when you closed it and it jammed the tissue in the slot even more it has happened to me a few times (and many of us) take the underbelly off not a big deal just a few bolts on each side and in the middle underneath peel back the underbelly material and you will have full access to the valve take the valve off and clean the old tissue and other gunk in the valve and while you are at it smear plumbers grease all over both sides of the knife blade to make it pull in and out better and reinstall no big deal just time consuming

i did my access flap like MFL.

I have one hole that i closed the flap, cleaned the edge surfaces with solvent and applied gorilla tape and heated it with aq hair drier.

Been three years and it still looks perfect.