Bounder: Black tank roof vent leaking black water

[PURALIFE]

We have a 2013 Fleetwood, Bounder, model 35K with a vacu-flush system, two toilets.
When the black tank was full, it would of course display full level reading. It would also, not allow the Vaccu-flush to operate showing a RED light at the indicator boxes in both bathrooms. This would clear once I emptied both tanks.
However, lately, the Vacu-flush works fine. But, the RED light does not show when the tank is full. Also, a small amount of black water came out of the roof vent. Of course, we emptied the black tank and cleaned up with appropriate fluids.

Has anyone had the same problem with their Bounder and the black tank roof vent releasing black tank water? and or also the Vacu-flush system not displaying a RED light indicating the Black Tank is full?
Is there a valve I need to replace? A switch to replace?

Now, the Vacu-flush pump is working fine. It is brand new; replaced about a year ago. There are no leaks at the pump, nor the toilets, nor the inside under the sink vents. No leaks at the black tank release valve to empty both the gray and black. Everything is working perfectly. Except what I described above with black water coming out from the roof vent.

Please, answer if this has occurred to your motorhome Vacu-Flush system. Especifically, the Fleetwood, Bounder series or one with similar system.
I appreciate your time and knowledge.

[Julia2005]

I don't know what the problem is, but wow, black water on the roof. Sounds like it is time for a chemical tank cleaning.

[pointrow]

It would seem to me the full sensor has failed. If it was working you wouldn’t be able to flush when full. Usually it’s the other way around, the sensor stops you from flushing when you know there is room in the tank.

Take care

Pointrow

[AlanTerry]

I agree with Pointrow, check the sensor wiring might have come loose or mice chewed. I believe the sensors are on the outside of the tank. Been awhile since hearing about the black tank content on the roof.

[computerguy]

I have a '16 and the float for the full tank pump shut off is internal from what I understand. I suppose a piece of TP could be blocking it from floating up and stopping the pump. May want to call REV and see what sort of sensor you have.
I've never filled mine to check if it even works. Hopefully never will either.

[Wootieli]

So I’m almost scared to look on the roof because in the last couple days when my Vacuflush is priming or pumping I hear this menacing gurgling in the wall between master and half bath which I understand is where the black tank vent runs up. I’m reading 2/3 full but I’ve had some sensor issues with it reading E also. So maybe I’m full and sensors are incorrect. Gonna empty today and hopefully rid myself of this demonic gurgle in the wall. It’s freaky, really. Sounds like ocean waves in the wall and that’s just wrong!