What the Heck is this?

[Travelling Three]

In our 2017 3661RL Montana under the bathroom sink there is a white water pipe coming in under the sink but not connected to the sink. This white water pipe goes to a black thing with an arrow pointing flow direction. There is another white water pipe that connects to this black thing and this pipe goes back down and through the floor, nothing connects to the sink or hot/cold water pipes. This black thing is square thing has somewhat of a T connector connected to it, this is where the two white water pipes connect. Anyway, it appears the black thing is leaking, so what is all this? Thanks for everyone's input.

[twindman]

Back flow preventer on the tank flush hose. I either had it plug up or leak (can't remember) and took it apart. There is a little 'ball' inside that slides in the tube - I think it got stuck. I took out the ball and no more trouble backflushing. I do need to use a preventer on the outside hose connection, tho.

[PackerFan]

That is your Black Tank Flush - Back Flow Preventer Valve.

Sometimes they might leak a little. I removed mine and connected the two pipes together.

[DQDick]

Took ours out when we bought the rig and now use an external one.

[mlh]

When it starts to leak if it does take it out and throw it away.
Lynwood

[BB_TX]

Originally Posted by PackerFan

That is your Black Tank Flush - Back Flow Preventer Valve.

Sometimes they might leak a little. I removed mine and connected the two pipes together.

And sometimes they leak a lot. Mine was made of clear plastic, cracked, and completely failed flooding the floor before I could shut off the flush. I also removed mine and use an external one.

[WeBeFulltime]

Ours is 5 1/2 years old and has never leaked a drop or otherwise failed and we are full timers.

[JandC]

Sounds like others have solved the mystery of the suspect pipe. All Montana units have them and they are worthless IMHO.


I am like DQDick. I used an external flush system (Flush King) on my Montana's and am using the same on current MH. I watched a video a few years ago about holding tanks. A tech had a black tank in his shop and demonstrated using the OEM type black flush system to clean the tank and then using a Flush King. The results were very similar but with the Flush King you can also close off your black tank and back flush/clean your gray tanks.

[Travelling Three]

[QUOTE=JandC;1057251]Sounds like others have solved the mystery of the suspect pipe. All Montana units have them and they are worthless IMHO.


I am like DQDick. I used an external flush system (Flush King) on my Montana's and am using the same on current MH. I watched a video a few years ago about holding tanks. A tech had a black tank in his shop and demonstrated using the OEM type black flush system to clean the tank and then using a Flush King. The results were very similar but with the Flush King you can also close off your black tank and back flush/clean your gray tanks.[

JandC, thanks for the reply. It sounds like you connected the two (in my case) white water pipes together, eliminating the black flush thingy, and are now using a Flush King system, correct? What is the purpose of the back black flush thingy anyway? I've had several campers in my life time and I don't recall seeing this back black flush thingy. Thanks again for your input.

[BB_TX]

The flush helps get additional solids out of the tank. It has a sprayer inside the tank. After completely draining my black tank, I turn on the flush, close the black tank valve, let the flush run a minute or so, open the valve and let it drain again, close the valve, and repeat 2-3 times. Each time I open the valve, a little more "stuff" comes out until it finally comes out relatively clear.

[Phil P]

Hi

Our trailer has the white pipes and came from the factory with only 2 90 degree elbows hooked together no backflow preventer.

Just another example of Keystone not building any 2 trailers alike and a total lack of quality control on the production line.

Phil P

[JandC]

[QUOTE=Travelling Three;1057261]

Originally Posted by JandC

Sounds like others have solved the mystery of the suspect pipe. All Montana units have them and they are worthless IMHO.


I am like DQDick. I used an external flush system (Flush King) on my Montana's and am using the same on current MH. I watched a video a few years ago about holding tanks. A tech had a black tank in his shop and demonstrated using the OEM type black flush system to clean the tank and then using a Flush King. The results were very similar but with the Flush King you can also close off your black tank and back flush/clean your gray tanks.[

JandC, thanks for the reply. It sounds like you connected the two (in my case) white water pipes together, eliminating the black flush thingy, and are now using a Flush King system, correct? What is the purpose of the back black flush thingy anyway? I've had several campers in my life time and I don't recall seeing this back black flush thingy. Thanks again for your input.

Generally speaking you can clean and rinse your black tank by 3 methods. You can use the built in black-tank-flush that most RV's come with, you can attach a Flush King to your sewer discharge along with a water hose, or you can simply hold the toilet ball open and fill the tank with water through the toilet.

On the video where the tech had a tank in his shop he demonstrated all three methods of rinsing a black tank. The OEM internal black tank sprayer that most RV's come with really didn't spray the sides of the tank much, but it did an okay job of adding fresh water to the tank for rinsing, as did the Flush King. I really think the whole idea of the video was to demonstrate one method of flushing these black tanks was as good as the next.

Since the back-check valve in many of these OEM black tank flush systems are cheap and fail, I have always hunted them down and did away with them. I always keep a Flush King attached to my sewer discharge pipe instead. I like having the extra gate valve at the end of my sewer discharge when traveling and disconnected from a sewer line. Plus, as I already stated, with the Flush King I can back flush each of my tanks individually, not just my black tank. We found that with extended use sometimes gray tanks can begin to give off odors due to food particles, grease, and just general junk that doesn't get washed out. I back flush my gray tanks on a regular basis. Hope this helps.