364 rear black tank

[rkulbok]

I had the exact same issue 2 weeks ago on my 328. In my case the tank would not drain at all. I tried using the black tank flush to clear the blockage. When I did this air pressure built up in the tank and when I opened the flush valve water and air began rushing up through the toilet.

I had to have the tank pumped by a septic company. During the pumping there was a loud pop, presumably the blockage, and the tank was quickly drained after that.

I am convinced there was a blockage in the vent that was stopping the black tank from draining and causing the pressure build up.

It has only been 2 weeks but I have not had any further issues draining the black tank.

Whenever I hook top now I always use the black tank flush to partially fill the tank with water.

[carmex]

Wanted to follow up to this old post. We finally got this resolved. I convinced the dealer to do the steps necessary to reproduce this and they immediately agreed there was a problem. They had been wanting to snake the vent pipe and whatever else they could to avoid actually dropping the tank and having a look. But when they did they discovered what I had been suspecting and what AquaMan suggested: that the vent pipe was 10+ inches too far down into the tank. They cut off the excess pipe and everything has been working great since then. They claim they'd never seen anything like that before. At least it's fixed now, but we know this happens, so don't let a dealer tell you otherwise and try to get out of doing the work.

[AquaMan]

Originally Posted by carmex

Wanted to follow up to this old post. We finally got this resolved. I convinced the dealer to do the steps necessary to reproduce this and they immediately agreed there was a problem. They had been wanting to snake the vent pipe and whatever else they could to avoid actually dropping the tank and having a look. But when they did they discovered what I had been suspecting and what AquaMan suggested: that the vent pipe was 10+ inches too far down into the tank. They cut off the excess pipe and everything has been working great since then. They claim they'd never seen anything like that before. At least it's fixed now, but we know this happens, so don't let a dealer tell you otherwise and try to get out of doing the work.

Glad they got it fixed for you!

[YellowSled]

I have a 2016 328, does the sink the bathroom drain to the black tank like it did in my older Winne or to the grey tank?

[carmex]

I can only speak for my 364, but the sinks drain into the grey tank.

[AquaMan]

Originally Posted by YellowSled

I have a 2016 328, does the sink the bathroom drain to the black tank like it did in my older Winne or to the grey tank?

With your gray tank empty, open the valve and turn on your bathroom sink. If water comes out, it's on the gray tank. If not, it's on the black. My Sierra had a bathroom sink that was on a black tank.

[YellowSled]

I was hoping it would drain to the black tank like my old RV did, but I guess the FR brand does it this way.

[AquaMan]

Originally Posted by YellowSled

I was hoping it would drain to the black tank like my old RV did, but I guess the FR brand does it this way.

It still may, check it out as described.

[YellowSled]

ill check it tonight. We hit the road for Florida tomorrow on its maiden voyage. Tks!

[AquaMan]

Originally Posted by YellowSled

ill check it tonight. We hit the road for Florida tomorrow on its maiden voyage. Tks!

Have a safe trip!