Outdoor sink piping plugged or backing up?

[EurekaJ]

Hello, I have a 2014 Silverado 36TB with and outdoor kitchen right behind my 2nd washroom. I had my sink plug a couple times. Do not know what happened the first time it plugged and how it drained. 2nd time it plug I removed the HepvO waterless valve and drained the water into a pan. I put garden hose down the black ABS piping and realized that it was plugged. Stuck a coat hanger down to the first elbow and nothing. I left it off for the afternoon and left for couple hours. We had family staying with us. I came back and found what seemed to be "black" water that had come back up the ABS pipe and flooded under my sink area. Maybe about 2 qts of water. Family had used the 2nd toilet and sink. I drained both 2nd tanks just to be safe.

Points:
1. We are permanently parked and everything is level. Black ABS pipe has lots of slope
2. It's possible 3-4 wood chips from smoker went down drain this year but they were small.

Questions:
1. Does the sink drain into my 2nd blank tank or my 2nd grey tank?
2. My black tank was on the fuller side but not full, either way the piping is above the floor and I could not see water down my toilet so the black tank could not be overfull and back up the outdoor sink piping as it is at least 2" above the floor
3. What's going on!! Help


pictures attached

 

[eddylives]

I had an issue with drainage in our trailer shortly after we were set up at a serviced site.
At first all was well but a short time later the draining became extremely slow and did not empty the tanks properly.
I finally took the 1.5 ft stinky slinky connection off of the trailer and removed it from the waste water connection at the site and..........there were a few large pieces of construction debris including a large cut out from a hole saw of plywood complete with the linoleum flooring glued to it.
I guess they just allowed the piece to drop into the black tank when they installed the toilet......and swept a few other pieces down the hole lol.
The pieces found their way out till they became lodged in the slinky and plugged it up......just something else to keep in mind.

 

[EurekaJ]

Thanks! I will also keep that in mind!

Hope someone else can help can shed some light on my situation.

Andy

 

[JWalker]

I do not know if the tank configuration is the same as our trailer, but it seems, in ours, the kitchen sink, the outdoor sink and the second bathroom sink, all drain into the second gray tank. Only the second toilet drains into the second black tank. Hope you can figure it out. Keep us posted.

 

[EurekaJ]

Okay, I think I may have figured it out. After testing last weekend and confirming 100% the rear washroom sink with an empty grey tank and after draining the rear black tank today. Here is what I concluded. The rear washroom sink drains into the rear grey tank and the outdoor sink definitely does drain into the rear BLACK tank. Don't know why it does as the black and grey tanks should be side by side under the washroom and the grey is closer to the outdoor sink on the outside wall. The kitchen sink drain piping also comes in under the rear washroom sink and straight down.

As as well my conclusion is that it drains somewhere into the side of the black tank and not the top of it. The 3 times my outdoor sink backed up, the black tank was not near full but full enough to cause the drain line from the outdoor sink to fill up with no place to empty. The time I had the HepvO valve off the drain from the sink leaving the black abs pipe open, when someone used the back toilet it must have pushed/forced some of the water out of the full abs pipe open under my outdoor sink. I guess displacing the air in the black tank.

Problem solved...... I mean problem identified and will know for next time when sink gets plugged to pull black tank.


Andy