Black Tank Problem

[bobdeb]

Returned home after short trip. Hooked up all systems and retired for evening. Heard a thunk sound, for lack of a better word. Got up and found the carpet at edge of bedroom next to bathroom wet. Went outside and found the black tank hanging down at the discharge valve side by about six inches. I was able to empty the black tank and it appeared to me that the discharge material was clearer than it should be. I also observed water dripping from the rig behind the tires for a length of 3 feet.
Turned off the city water and dripping stopped. My initial thought was that some how fresh water filled the tank and that additional weight caused the tank
to drop, except the seal inside the toilet was intact.
Is there another way the fresh water can enter the black tank other then when it is flushed?

2008 Greyhawk 30GS.

[Jimmyd]

Bob, if your coach is like our 2016 Greyhawk I would look under the bed first to see if there is a leak in the water manifold. Next you should check the Check Valve which on our coach is in the cabinet under the bathroom sink where the fresh water enters the coach for filling tank etc.
The tank dropping may just be a strap that has rusted off. Not much holding them up in place. Good luck hope you find the water source. Jimmyd

[bobdeb]

Thanks. The rug is dry around the bed so I think I'll check under the sink where the pump is. If the check valve failed that could explain water on the floor but I'm still concerned on how the excess water got into the black tank. I have a clear elbow on the discharge and the stuff coming out was not the, excuse me, brown color it normally is.

[Jimmyd]

Bob, it seems like if the toilet is holding water without leaking down into the black tank then the most logical answer would be the Check Valve has failed. I would check that for sure. It could contaminate your fresh water tank. Let us know how you make out.

[Fr8Train]

Accidentally hook up to the tank flush?

[Robbbyr]

Originally Posted by bobdeb

Is there another way the fresh water can enter the black tank other then when it is flushed?

2008 Greyhawk 30GS.

My first motorhome (1992 Gulfstream) did drain the bathroom sink into the black tank, but all "newer" units I am familiar with only drain the toilet itself into the black tank. That means any water enters the black tank through the toilet or the tank flush, if equipped with one.

All units I have seen have a completely separate water inlet connection for the tank flush if equipped. But I have seen examples where prior owners modified the plumbing so they had a valve they could open allowing water from their regular freshwater inlet to flush the black tank. I guess it was to save time, disregarding any health concerns it might create under the right (wrong?) circumstances.

Leaking toilet water flush valves could overflow the bowl causing floor wetness, but usually the toilet flapper would have to be partially open to fill the tank. Is it possible it was slightly open so water filled the tank? Or like mentioned above, any chance the tank flush was connected?

[bobdeb]

Well thank you all. What happened was my sewer flush hose which I use after I empty the tank was minutely cracked open. In 10 hours or so it filled the black tank and then leaked around the floor seal, onto the bathroom floor and subsequently the bedroom rug. I managed to jack it up in place and reattach the bracket.

I am good to go. Again thanks.

[Robbbyr]

Glad you found the source, hope the clean-up goes smoothly. I did wonder about the way the tank was secured, it did partially fall when completely full. If the unit was mine, I would see if there was some way to reinforce the method used to support the tank. My concern would be for the future when it might be close to full and not with just clean water! Or even less full than that, but bouncing down the road on a less than perfectly maintained highway. I would be very concerned about it coming loose again.

You also mentioned it just dropped on the outlet end. Is there a way you can inspect the fitting to the toilet itself as well as the vent line connection? I would be worried those connections could have cracked or become dislodged when bent down at an angle, possibly creating leak points for liquids and/or gasses to escape.

Not trying to be Mr. Doomsday here, but I would not want a problem on future trip to "present" itself unexpectedly!

[bobdeb]

100% correct. I ran a charter boat fleet in the VI. 50' RV's on the water. Nothing worse then repair time that isn't used to improve the installation. I envision some hangers, fasteners, and additional brackets in my future. The tank actually landed on my retracted leveler, so ne pressure to bear on my outlet pipes. Again thanks.

[Love To Travel 2]

Years ago, I was talking to a neighbor in a campground who told me about a similar experience. He would shut down his travel trailer during the week, but every weekend he and his wife would return for three days. One Friday evening he returned, opened the door, and was greeted by a torrent of water as it exited his rig. He discovered that his black tank flush hose, which he kept permanently connected, was leaking slightly, which over the course of a week had filled the black tank, somehow overflowed, and covered the floor with a stinky mess.

From that day forward, I keep my black tank flush hose in the compartment, and it only comes out for the time it takes me to dump, flush, dump, flush, dump, and flush. A lesson learned.