leaking flush water line

Hello all !
I am new member, I bought the used sundance 5th wheel recently and got a problem. A problem to me (only I hope ) and looking for an advice. The black tank flush water line is going from the connection box a little bit down, then turns up and going thru an opening in floor ( - about 3" Dia ) somewhere under the shower. There is a leek, when I connect the water hose, a water spray thru the opening . I cannot reach a spot or even see where it leaks. Most probably in an elbow connection, but just a guess. Anybody would know a trick how to get to it ?
Thanks,
reka
reka2@shaw.ca

You didn't mention which model you have, but if there's a black flush on it, then there's an anti-siphon valve hidden in the wall above the toilet. That has been a common leak problem. With some models, it may be possible to find the valve by removing the round, white close-out in the shower stall wall. In others, it is behind the wall panel and an access hole needs to be cut to get at it. In mine, a BH3670, I can access the lines to it from the basement (removing the rear panels) and pulling it down.

So far, mine has not leaked, but if it ever does, it will be removed.

We can get to our anti-siphon valve by removing the access port in the shower.

The problem is probably a broken valve due to the anti-siphon valve freezing because the black tank flush was not winterized, we had that problem the first year we had our trailer.

So far, mine has not leaked, but if it ever does, it will be removed.[/QUOTE]

This is the important part of John's post. If you can find it remove it, if you can't find it eliminate it. Thats what I did and mine was ok.

Question, did you have a pressure regulator on the hose. If you did not and were putting city water pressure to it.....trust me...you will have a leak.