black tank rinse leak

[Steamboat_Willie]

We encountered a black tank rinse related leak on our 2012 22FB this week. As the black tank was draining I turned on the rinse water, as a I always do at about the 50% point (guessing) and as it drained just fine as always, I noticed that there was some water dripping from underneath in the back of the camper just past the outside drain hose connection. That unreliable relief valve (which we replaced last year) located in the bathroom closet was not the problem this time. (It was bone dry.) Could it be some residual water emerging from the toilet flange somehow? Anyone encounter something similar?

Also, what's the deal with that black, rubbery-like (??) sheet stuff that I discovered up underneath the trailer in the back? In order to get up in there under the toilet and tub in order to inspect for the source of the leak, I'm guessing that I have to cut that stuff open with a utility knife to see up in there? Really? And then how do I close it all up when I'm done? Does that mean I have to custom cut & fit some thin plywood in some manner to close it up? Anyone have any experience with this?
Thanks
Eddie

[jws0679]

I found that where the water line screws on to the black tank flush at the tank had backed off a little on my 2015 338rets. I pulled some of the screws out holding up the black plastic liner on the frame just enough so I could pull it down a little and reach the line. I just tightened the line up real good and it hasn't leaked since. It was a little bit of a pain to get the holes in the plastic to line back up with the holes in the frame, but not too bad. A lot of dealers just cut a hole in the liner and then screw a larger piece of plastic over it.

Jon

[Grumpy]

Black gorilla tape seals it back up very well too.