Water Leak Question

[GreyWolf67]

So, when I rinse the black tank from outside with the hose, I get a leak dripping. I found where, inside, in this access point, where the water comes in, it goes through the black valve thing that reminds me of those little devices you see for the washing machine water feeds in a house, let's air escape or something. Pics posted, what is this black valve thing and can I remove it all together I'm wondering.

The white elbow connecting to the white hose going downwards is where it's leaking and I have the smell of the black tank in the TT when flushing the tank, draining, rinsing and when it's getting near full.

Thanks.

[BFlinn181]

In a hook up of potable water connected to the black tank flusher, you want a back flow valve, an anti-siphon valve, or the like. It's to prevent any black tank liquids from backing up into your fresh water supply. I'd replace it, not just remove it. I couldn't find a duplicate of what you have, but it's needed. Take it to a plumbing supply to have it identified and replaced.

[Nut4speed]

The "correct" answer is to replace it. However if it was my camper I'd just remove it. The chances of fluids from your black tank backing back up the nozzle in the tank through that hose and into your pressurized water hose is slim to none.

[rrtribble]

In all likelihood our smell is coming from the leaking line and not the valve.

It looks as if the elbow is on the tank side of the valve, therefore it is not the valve that is leaking bu the elbow, if i understand your post correctly. I would disconnect the valve from the hoses, beginning with the input hose followed by the valve. Now you have the elbow and corresponding hose free to inspect. Check for any cracks as this is most usually the case. If it is cracked, replace it and reconnect everything and you should be okay.
If no crack located, connect a water hose to the elbow and run water through the to the black tank; this may require a hose fitting going from your hose to the elbow but you can purchase one from most hardware stores. If leaking, verify where and you'll need to cut the hose and put in a new elbow. If no leak, check the gasket between the elbow and the valve.

Contrary to the above post, removing the backflow valve completely WILL allow bacteria to contaminate the hose and water supply source. This is one thing you do not want to happen.

Best of luck - keep us informed of how the repair goes as I'm sure someone else will have the same problem too.

[lynnmor]

It's a vacuum breaker probably with a check valve. Throw that thing away and add or make sure there is a check valve in the line. Even the vacuum breaker manufacturer will say that water will be expelled under certain conditions. Junk!

[GreyWolf67]

Thanks for all the responses, just to be clear, it's the "Flush Black Tank" line in, not the fresh water in. It is only when flushing out the black tank after a draining.

[BFlinn181]

Originally Posted by GreyWolf67

Thanks for all the responses, just to be clear, it's the "Flush Black Tank" line in, not the fresh water in. It is only when flushing out the black tank after a draining.

But where does the water come from that flushes the black tank? The device is there to prevent water from flowing back from the black tank flusher into the water supply. Most every sprinkler system is required to have one to prevent contaminated water from flowing from the yard heads back into the house water system. I have check valves on my tank flushers.

[GreyWolf67]

Makes sense, will get after it and report back.
Thanks.

[wingnut60]

It is a common item--every RV parts store should have one, or get it from Amazon. You can replace it with identical plastic one or get a more expensive brass one, not sure which will last longer. Just be sure the anti-siphon valve itself is leaking and not the connections.

[Polyian]

When I first used my black tank flush I had water spraying everywhere from that connection. It was tight but it leaked. I undid it and put a couple of wraps of teflon tape on the threads and no more leaks...cheap fix to try before you toss cash at new parts.

[GreyWolf67]

FIXED - It was the cheap plastic hose clam from the factory. I replaced it with a metal hose clamp and no more leak. In the pic attached, I'm holding the plastic part removed, next to the new clamp installed.