Sewer Flush Leaks

[MrMeeks]

Montana 2955 RL, WATER LEAKAGE when hooked up to flush black tank. Water inside and out. Previous recommendations were to inspect area under rear vanity. Can I access from cargo area? Are connections accessible under step up interior plates? I guess if I can look under neath while circulating water in system, hopefully finding water problem. Any other hints??

[BB_TX]

Common problem with leaking/failed black tank flush antisiphon/vacuum breaker valves. Sometimes that valve is located under the bathroom vanity sink, or possibly under the kitchen sink. And sometimes, like mine, they are inside a wall, typically behind the shower. Hopefully yours is under a sink/vanity where you have access to it. Look under your sinks for two extra pipes with a small plastic box like device at the top.

You don't give the model year of your 2955RL, but I think it is similar to my 2007 3075RL. And as mentioned above, that valve was in the wall behind my shower, and between that and my entry closet. Had to cut an extra opening in the back of that closet for access. If that is your case, I can post some pics of my repair.

Some have replaced them. Some of us have simply eliminated them and use an external antisiphon/check valve.

[Carl n Susan]

On our 2005 2955, the anti-siphon valve was behind the shower. Open the kitchen cabinet left of the refer and look for an access plate. You will have to close the door to the bathroom in order to see/access the valve. It is not uncommon to discover the access hole is not in the best location for repair and you have to cut a new one. But it is inside the cabinet where it won't be seen.