Black tank flush out pump and inlets

[WearyTraveler]

I bought a "Camco Antifreeze hand pump." I tried to pump antifreeze into the "sewer tank flush" inlets.

On the front tank, I pumped about 1/3 gallon in, so I'm pretty sure that there's antifreeze throughout the pipe all the way to the black tank. However, when I unscrewed the pump's tubing, a bunch of antifreeze came back out. I thought that there's a check valve in there that's supposed to prevent backflow?

On the rear tank, the inlet would not let any antifreeze in. It appears to be blocked internally. I pumped and as soon as the pump's tube was full, it wouldn't let me pump any more. I tried to pump harder and it popped the tube off. I'm ASSuming that the check valve is malfunctioning or that the tube / pipe is blocked somehow. How do I rectify?

Am I supposed to do something special to make these flush inlets work?

Thanks in advance for the help!

 

[Porkchop-THOR]

The back flow preventers are located higher than the inlet point. Any liquid in the line between inlet and back flow device will run back as gravity requires, so that is normal.
On the back unit=are you sure that there was proper flow there before? It would not be the first unit to leave the factory installed backwards, which would prevent flow the proper direction + would allow flow the wrong direction.

Bill

 

[PopFla]

As far as the first tank goes, any antifreeze in the pipe between the exterior connection (#1 on the diagram below) and the check valve (#3) will drain out when you disconnect the antifreeze pump. Depending on how long that section of pipe is, it may hold a considerable amount of antifreeze.

Regarding the second tank, I'd have to agree and suspect a defective check valve.

 

[WearyTraveler]

You guys rock! I don't care WHAT those Forrest River owners say about you!

So - it appears that for the front tank, I should be good.

And - for the rear - my only real exposure (if it's installed backwards) is the small length between tank and inlet. It's only a couple of inches from what I can see, less than a foot between inlet and rear tank.

We're heading to Florida next weekend to stay with Jamie's brother for a week or so. I'll try to dismantle it and get it squared away while down there in the warmth!

 

[WearyTraveler]

The back flow preventers are located higher than the inlet point. Any liquid in the line between inlet and back flow device will run back as gravity requires, so that is normal.
On the back unit=are you sure that there was proper flow there before? It would not be the first unit to leave the factory installed backwards, which would prevent flow the proper direction + would allow flow the wrong direction.

Bill

Not sure. The RV is new to me and I'd doubt the previous owner ever back flushed the tanks. So - I think (well, hope) that there's no water in that pipe. We'll see when I get to Florida and start mucking with it...

Thank you!

 

[Porkchop-THOR]

I received a new unit one time that I noticed the tank flusher was not working. Located the backflow device and just turned it around and all was good. Pretty easy fix if that is it. Just hook up a water hose and if no go simply reverse and you're good. Good luck

Bill