What is this part and what does it do?

probably a back flow preventer.

The anti-syphon devise is to be located above(higher in elevation) than the incoming and outgoing lines to work properly and not to leak. Maybe it just fell over from the upright position? Maybe just needs to be straightened out and raised to stop leaking. But if you winterize, freezable water could get caught in there and freeze if not drainable on both sides.

sch911 wrote:
Yes it's a vacuum breaker. And yes it's installed upside down. This has already been pointed out by others but of course many don't read before posting. Just change the orientation so the top (with the screw) is up and you're good to go.

Exactly.....

The bell shaped top is what allows air in so the water can drain after supply has been turned off.

Water is dripping out because it's upside down.
Flip it UP and secure it so it stays UP

Well, I'll give that a shot before replacing it. Seems odd the manufacturer would have installed it that way and its been in this position for 6 years with no leaks noticed. Another person who replied added that his is in the same place.

Yes it's a vacuum breaker. And yes it's installed upside down. This has already been pointed out by others but of course many don't read before posting. Just change the orientation so the top (with the screw) is up and you're good to go.

Was able to take a close up photo, found that the vacuum breaker is made by Swan Industries. They want $61.95 plus shipping for this little guy. I think I'll spend a little time researching a less expensive and more reliable brand this weekend.

rcknrbn wrote:
Thanks for the quick responses. You guys nailed it, it is definitely in the black tank flush line. I went outside and turned on the flush and the line started humming with water. The leak isn't coming from the threaded fittings but rather from the bell shaped housing or shroud pictured in the lower part of the photo. I'll tear into it this weekend and see if there is any debris or something cleanable. If not, any recommendations of an online site to order a replacement from?

Look for a part number and/or manufactures name on it and call the RV manufacturer to see if they can help.

Thanks for the quick responses. You guys nailed it, it is definitely in the black tank flush line. I went outside and turned on the flush and the line started humming with water. The leak isn't coming from the threaded fittings but rather from the bell shaped housing or shroud pictured in the lower part of the photo. I'll tear into it this weekend and see if there is any debris or something cleanable. If not, any recommendations of an online site to order a replacement from?

chipper wrote:

HappyKayakers wrote:
I have a fitting like that for my black tank flush system.

Thats what it is. A vacuum breaker to the black water tank flusher.

X2

Mine looks a lot like that and its in the same place.

It's a vacuum breaker like previously mentioned, it should be in an upright position so that the top with the screw in it is up. Sometimes a little piece of debris can get stuck in there and cause a drip, I have seen spider webs cause problems in some when used in an outdoor application.

I sure wouldn't take it out of there it is there for a purpose. If it is on the line to the black tank flush I sure wouldn't want to risk the chance, no matter how small, of black water being pushed back into the fresh water system.