Leaky Black Waste Valve and tank bracket failure

I have finally gotten tired of being covered in poo when emptying the black waste tank. The valve leaks a bit and it must build some pressure with the cap on the dump tube. When I take off the cap, the waste spews out (have you seen the movie RV?) So I decided to pull off the underbelly and have a look. I found the valve, but also noticed the brackets holding the black waste tank were twisted and the tank was falling out. The tank is held in place with 2 pieces of steel stamped into a 90 degree bend (like angle iron but not nearly as strong). The front bracket was welded in place and the rear was held in with 4 bolts (2 each side). One bolt broke or was never installed and the bracket twisted allowing the tank to drop about 2 inches. So I have fabbed 1 new bracket and a brace for the other using 2" angle iron.

I plan to finish this fix tonight.

Back to the original problem - I am guessing there is some debris in the valve. I want to remove and clean/inspect the valve. I see 4 bolts holding the valve together. Can I simply remove the 4 bolts and slide the valve out? It looks simple and I assume it seals to the rest of the plumbing with an O-ring.

Any tips on removing the valve? I want to get this fixed ASAP so we can head out on a trip soon.

Thanks!

TXBobcat started a thread covering this exact thing with great pictures and all. Here is a link that I hope works. It cover replacing a valve for a grey tank but the valve design/concept is the same. //heartlandowners.org/showthread.php/14106-Gray-Water-2-Replacement/page3?highlight=txbobcat

Thanks Ray - I didn't find anything doing a search - tax season and I'm fried!

Dmaxcc6spd, I had to remove my valve one time, and was not too bad. In my case on the Bighorn, one of the grey water drain pipes splices into the black water pipe. That prevented me from separating the black water valve. So after removing the four bolts on the valve, I had to cut an inch out of the grey water pipe so I could be able to move the black pipe to separate the valve. I spliced the grey pipe back together with a rubber coupling I got from the Home Depot plumbing department.
One thing I have found is that now I always use the black tank flush after dumping. I think that if a person does not flush the tank, then some TP may be in the valve when closing. Then when you close the valve it eventually packs into the gasket and prevents a good seal, therefore allowing a leak.
Good luck with your project.

Peace
Dave

Thanks cookie. That's what I am thinking happened - but I always use the tank flush - I was really excited to see the tank flush feature on the Sundance for 2010! It's really bad when you get excited about stuff like that!

Try this link to see a video on rebuilding valves.
http://blog.rv.net/2010/04/rv-waste-valve-maintenance-repair-replacement/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+RvnetBlog+%28RV.net+Blog+Daily+Updates+Feed%29

Dmaxcc6spd said:

Thanks cookie. That's what I am thinking happened - but I always use the tank flush - I was really excited to see the tank flush feature on the Sundance for 2010! It's really bad when you get excited about stuff like that!

Click to expand...

I'm a firm believer in adding a few ounces of Dawn dish washing detergent
to the Black and Gray tanks (keeps things slipperly so less debris get stuck in the gate seat of the valves.)

An alternative, or temporary fix, is to install a twist-on valve at the sewer connection. At least you won't get the build up and spray when you loosen the cap. Had that problem with our TT.

I was thinking of the twist on, but now I'm in so deep, I might as well find the root of the problem. I guess it was a good problem as I found the broken and falling tank before it did severe damage.

The day I bought our fifth wheel I also purchased the twist on valve and put it on that day and stays on. so now I have a double valve. When ever I dump I first dump the black tank and flush a little bit. Then I will close my valve I put on leaving the black tank open. Next I will open my gray #2 tank and let it equalize with black water tank. Close the Gray, open the auxiliary valve and drain the black a second time. I do this one more time, flush with the tank flush and then open all the drain valves and let the tank flush run. I also put in the dawn and some calgon water softner liquid that I get from walmart. Questions?

Even after fixing the damage and the main valve, having the secondary one in place may keep you "dry" should something get stuck in there, again. I put a short, clear extension (HydroFlush adapter) between the sewer connection and the external valve just so I can see if there's a "surprise" waiting behind door #2.

I use the tank flush and the back flush method to try and thoroughly clean the black tank. If you feel any resistance when closing the black valve, don't force it to close. It's time for some serious flushing action until you get the jam out of there. Once it's forced into the slot for the gate, it's not coming out on it's own.