TAB 400 Black Tank Flush Port

falcon1970

Does the black tank flush port just fill the black tank or does it have a rotating spray nozzle in the tank to wash the sides of the tank?

Jilong

In my T@B 400, I've looked down the toilet into the black tank while I had a hose connected to the black tank flush port. To me, it looked like a spray, but maybe not a rotating spray.

falcon1970

So there is probably no need for one of those wands with the rotating heads from Walmart.

sunshine

Falcon, We have a 400 also and the following works great. Dump Black Tank first. Close Black tank valve and dump grey tank. Close Grey tank valve, OPEN Black tank valve, hook up garden hose to flush port and turn on city water. I ALWAYS see "extras" and toilet paper drain while flushing through port with city water. Let's me know the flush port works well as installed.

falcon1970

OK, seems that there is some sort of spray on the walls of the tank rather than just a fill port,

Michigan_Mike

falcon1970 said:

Does the black tank flush port just fill the black tank or does it have a rotating spray nozzle in the tank to wash the sides of the tank?

I believe that the black tank flush system has a built in rotating spray nozzle inside the tank.  I purchased a small, clear section of pipe (approx. 4" section) that adapts to the discharge port between the gray/black handles where you hook up the sewer hose.  This allows you to see the discharge color of the water.  

What I do is hook up the water hose to the side of the trailer (for the black tank) that is at the fixed location at the dump station.  After I open up the valve and dump my black tank I then close up the valve, turn on the water supply at the dump station and run it for about 20-30 seconds.  I shut it off and then dump the black tank again.  Any residual waste should dump out and I'm able to gauge the cleanliness by seeing the water via the clear section of the pipe adapter.  I will do this process a couple of times, dump the tank and then after opening it a second time I run the water hose with the valve open until the water is clear exiting the black tank.  Once done I then dump the gray tank which completes the dump cycle and also cleans out the sewer hose.  

I also add in some dish soap and occasionally some Downy fabric softener into the black tank (when I'm prepping the tank after dumping it) to keep the material moving around and hopefully to eliminate any issues with waste inside the black tank.  If you are camped in a fixed location for a long time and people are using the toilet the material  gathers in one spot and although not a pleasant conversation topic, something you should take into consideration as it can create some issues later if you aren't proactive.  I have a 29' travel trailer parked in a fixed location in Arizona and have dealt with the issue and it's not fun trying to open a plugged RV pipe.  Just sayin'!  

Here is a short video that gives you the basics and an idea of the various black tank flush systems that are out there and what they do.  

https://youtu.be/Lf4p1CpfgOs?t=3