New issue with gray water tank

[Buckleup]

This just started about a week ago. When the shower is used I notice water coming from the top area of the gray water tank and raining down under the 5er. I drained the tank and all was well until it started getting full again. The basement has the drain pipes going down through the floor directly into the tank and it looks like there is a vent pipe on the roof for the gray tank but it is inside the wall and not seen in the basement. I will probably have to drop the tank to find out why it leaks from the top, however it looks like I will have to cut the pipe going to the dump valve and then install a rubber coupling to reinstall the tank. Would anyone know if the tank has seals on the top for the tub/sink drain and vent? We have a 2013 Palomino Puma 5th wheel.

[Buckleup]

Therink, the lavatory drain connects to the shower drain and it passes directly through the floor into the gray tank, no leaks above the tank entry at the floor. This is why I believe there should be some kind of seal that has failed. I will probably call our dealer on Tuesday when they open before I drop the tank. Looks like one metal bar with four bolts to be removed and the pipe to dump valve that will have to be cut and the tank should come down.

[therink]

It could be the drain pipe flange or P trap that attaches to the shower pan. I would check that first if you have access before dropping the tank. Does your tank also store water from the lav sink drain? Does the tank area also leak when running water down shared sink drain.