Black Tank Flush Leaking

[tramponi]

I am new to the travel trailer world (this is my first post) and recently purchased my first travel trailer which is a 2010 Rockwood Ultra Lite 8314BSS. While out in it over the weekend, I drained the black tank and was starting to flush it when water started pouring out under the trailer through the underbelly. I have used the flush line before with no issues, but not this time.

From reading posts, it seems that the line or connection going into the tank most likely either broke or came loose. The water leaking through was clear and had no smell so it doesn't seem that the leak was from the black tank.

Since it seems I am going to have to cut into the underbelly to find the failed connection or leak point, where do I start my search? How do I know where to cut into it at so that I can minimize the number of places I need to cut out to make the repair? Is a schematic available that shows a probable location? Or is there a better option?

Love the trailer, but don't want it to turn into finding/fixing one problem after another.

[Oaklevel]

It can depend if the black flush line was factory installed or end user installed. I have installed 3 on campers myself.

Doubt that there is a schematic available for a 2010.

In the grand scheme of things a leaking tank flush is minor and nice to have but does not affect your use of the trailer.

[fonzie]

Try to find your black tank flush anti-siphon valve to see if that is what is leaking.

See post #8

https://www.forestriverforums.com/fo...nk-192488.html

[Oaklevel]

Originally Posted by fonzie

Try to find your black tank flush anti-siphon valve to see if that is what is leaking.

See post #8

https://www.forestriverforums.com/fo...nk-192488.html

I would do that first if you have a factory installed black flush. It will not be set up like that, set up if the flush was added later.

[tramponi]

I will try to find the anti-siphon valve next time I am at the trailer in two weeks. From all I can tell, the trailer was set-up with the flush when originally purchased. If the leak was at the anti-siphon valve, would I see water inside the trailer because I don't?

[Skip12]

Depends where the anti-siphon valve is. When it happened to me, my anti-siphon valve was behind a wall, behind an access panel. Therefore, I had no water visible in the camper but it sure did pour out of the bottom just like you described.

[fonzie]

Originally Posted by Skip12

Depends where the anti-siphon valve is. When it happened to me, my anti-siphon valve was behind a wall, behind an access panel. Therefore, I had no water visible in the camper but it sure did pour out of the bottom just like you described.

Look below the television, there should be two doors that can not normally be opened. Remove the screws on the door next to the outside wall. Your water pump and anti-siphon valve should be behind.

[The Evil Twin]

I'm no help on the location in that model, but you might try hooking up air to the black flush line. You might be able to hear where it is coming out before you start cutting things.

[tramponi]

Originally Posted by fonzie

Look below the television, there should be two doors that can not normally be opened. Remove the screws on the door next to the outside wall. Your water pump and anti-siphon valve should be behind.

I was in that cabinet area over the weekend removing the water filter before I had this issue. At that time I wasn't looking for the anti-siphon valve but there were water lines and the pump in that cabinet. After it had leaked I went back in to the cabinet to reinstall the water filter and didn't see any water in there, but I guess it's possible I could have knocked something loose while I was in there causing water to run down the pipes. I will definitely check this out.

[markb422]

The after market ones just have a female garden hose connection with a check valve in it to prevent back flow. I have installed a few of them and have seen them leak. Usually at the garden hose connection where the hose screws into the flush.

[JLGulick]

I have a 2020 Flagstaff Super Light 2806fkb and had the same issue with water flowing from under the trailer while flushing the black tank. I also had water flowing under the bathroom vanity. The vacuum breaker valve is located under the bathroom vanity on my trailer. I removed the valve and flushed it out. In Pennsylvania we have Stink Bugs and in the fall they look for winter hiding places. There were 5 Stink Bugs that I flushed out of the vacuum breaker valve. I was very impressed with these little guys. My remedy was to purchase a new valve, same make and model and I zip tied a fine net stocking over the top of the valve before reinstalling it. I have used it since and have had no water leading from under my camper or the vanity.
Joe

[Philandterry]

My anti-siphon valve was bad and it leaked out the bottom of rig. The valve was behind the shower knobs. I just had to loosen the shower Knob assembly, pull it forward, and replace the valve. It would have helped if my hands were smaller.

[millman75]

My anti-siphon valve only started leaking after a couple years service, located under a bathroom sink, and looks like this:

[jeff64]

I had a leaker with the black one too a few years back. Valterra makes a clear one that's been doing the trick for about the last 4 years

[Bodro]

I had a similar issue with a Jayco. The problem was the plastic check valve which didn’t get winterized and cracked over the winter. Lesson learned...winterized the black tank flush.

[tramponi]

Life has seriously gotten in the way and I am finally getting back to this. .....I did find the anti-siphon valve, and it was below the TV in the cabinets as fonzie had mentioned. Last weekend, I put compressed air (30 psi) into the black tank flush connection and listened for leaks. All I heard was a lot of knocking at the valve location. I didn't hear or feel any leaks but just the knocking noise. I didn't have the courage to put water back into the flush yet. Any thoughts to what may have caused the knocking noise?

[Mch5jdm]

Originally Posted by tramponi

Life has seriously gotten in the way and I am finally getting back to this. .....I did find the anti-siphon valve, and it was below the TV in the cabinets as fonzie had mentioned. Last weekend, I put compressed air (30 psi) into the black tank flush connection and listened for leaks. All I heard was a lot of knocking at the valve location. I didn't hear or feel any leaks but just the knocking noise. I didn't have the courage to put water back into the flush yet. Any thoughts to what may have caused the knocking noise?

Maybe the sprayer inside the tank has a spinning sprayer and you hear it going around. Just guessing thought.

[tramponi]

The knocking felt like it was in the anti-siphon valve though.

[kenandterry]

......and the problem with hearing noise from a system of pipes, valves and connections, is that the noise could be coming from something that is not fastened as secure as the actual source of the noise.

Is the location of your anti-siphon valve, anywhere near where you do see water?

[markb422]

The knocking might be an air admittance valve opening and closing.