Sani flush leak - MW22R

[jnkdad]

Hi folks,

I have a strange problem with the black tank flush system leaking. I tried searching the forum for answers, but the search feature doesn't appear to work very well, so sorry if this has been addressed in another thread.

I connected the hose and turned on the water and saw water dripping out of the trim that runs along the side above the dump valves.



I checked the plumbing diagram and it appears the tubing runs from the hose connection behind the shower up to the shower valves, then back down through the floor to the black tank. Not sure I understand why it was designed that way, but how the heck to you get access to that without ripping the shower out??

[Motts461]

I just repaired my Sani Flush system, Minnie Winnie 31G. The connection between the vacuum breaker and check valve started leaking. The strap that supported everything was missing. I had to remove a magazine holder in wall to access mine and repair it. I guess science dictates the vacuum breaker needs to be above the tank, probable why Winnebago mounted it like they did. I agree your vacuum breaker and check valve are connected behind shower faucets. You would think Winnebago would make this accessible on yours also.

[Geosman]

Been there in several situations. Your local Home Depot / Lowe’s store should have a fairly inexpensive fiber optic scope in the tool department. I use one by Milwaukee. I think Ryobi has one also. I make a 1” hole with a hole saw bit as an inspection port to explore the space with the fiber optic scope. It’s pretty easy to find a 1” plastic cap to use as a hole plug if the inspection shows no signs of a leak.
If I do find a leak area that needs better access the same home stores have plumbing access covers made by Oatey they come in all sizes and are made to frame a cutout access hole along with a snap in plastic panel for future access. They save a lot of fuss and bother when making repairs in walls or ceilings. The frames can be attached with construction adhesive or silicon sealer.
Good luck locating your leak. I found mine at a Fernco fitting at the intake of my macerator pump. Getting to the pump at the back wall of the water control bay was a 4 hour ordeal. Once removed I rebuilt the pump impeller section and relocated the pump and tank piping for improved future access.

[Geosman]

Originally Posted by jnkdad

Hi folks,

I have a strange problem with the black tank flush system leaking. I tried searching the forum for answers, but the search feature doesn't appear to work very well, so sorry if this has been addressed in another thread.

I connected the hose and turned on the water and saw water dripping out of the trim that runs along the side above the dump valves.

Attachment 174163

I checked the plumbing diagram and it appears the tubing runs from the hose connection behind the shower up to the shower valves, then back down through the floor to the black tank. Not sure I understand why it was designed that way, but how the heck to you get access to that without ripping the shower out??

Was your black tank empty when you started the flush water? If it was full it’s possible you were overfilling it? It’s gotta go somewhere. A few have discovered it squirting out around the toilet flange.
Just asking because I think I see a macerate pump connected to the sanitary and a hose that likely runs to a sanitary drain/toilet. These operate slowly as they need to chop up and pump all the solids through a garden hose and if you are adding extra water during the flush operation. It may be overfilling the tank and producing the leak you experience.