Black water flush check valve leak

[goofey chuck]

Under the sink I had a leak coming from a check valve I believe is hooked to the black water flush system????

[fonzie]

Not much info given, trailer type, year etc etc...what is your question?

[goofey chuck]

2014 primetime tracer 3200bht the valve is leaking on the bathroom floor

[fonzie]

If leaking on bathroom floor when water hose is hook up to black tank flusher outside, then you will most likely need to change it.

[BigJohnD]

It's required by "RV" code. I always take them completely out. Most of the one's I had, leaked at some point. By their code, it has to be mounted at / above the toilet level. That's why you see them under the sink a lot, or sometimes in a wall. It is supposed to prevent black tank water from going back into your hose at the inlet. But, if you look at the way the systems are installed, and how you flush a tank, this is unlikely to ever happen. We use a designated hose regardless. Assuming you've removed it like I have, to contaminate a hose, you'd have to have the tank above half full submersing the nozzle in the tank. Then it'd have to syphon out of the tank through those tiny jet holes.

Regardless, you can replace it if you want. The next one will probably leak at some point, and next time you may not be watching it and create some water damage.

Ever look at an aftermarket set up? Some come with a vacuum breaker, that installs right at the inlet. There is no "above the toilet" breaker installed.

[goofey chuck]

What did you replace it with?

[BigJohnD]

On some, just 2 pex 90's and a short piece of pex. Just cut of the threaded fittings and crimped the 2 90's and piece of pex in its place. On our present one, I pulled the whole thing out from under the sink and put a pex union in the basement.

[goofey chuck]

Thats it exactly.... what size do you think the thread is?

[BigJohnD]

Same size that fits to any standard faucet. You can purchase the male thread x pex at lowes or HD. I don't know the exact size, but I didn't utilze the threads. I cut the pex pipe just below those threaded fittings at the same level. Then, just 2 - 90's and about a 1.5 inch piece of pex between.

[goofey chuck]

Ok thanks!!!

[BigJohnD]

Cheesy quick sketch, but you see what I'm referring to.

[fonzie]

Originally Posted by BigJohnD

Cheesy quick sketch, but you see what I'm referring to.

I will do this mod on my camper before mine starts leaking. Thanks

Here is a short video on Pex fittings for Goofey Chuck

https://www.youtube.com/watch?v=q8J1yHRuFWs

[BigJohnD]

As most know, for every 90 or fitting there is a bit of a friction pressure loss. Really not enough to affect this system, but there is some. Depending on your set up, you might be able to completely eliminate the piping under the sink, and just put a union in somewhere opposed to the U shaped insert. In one fifth wheel we had, it was way up in the wall between the shower and TV. In this case, we traced everything back down to the basement, and probably eliminated 6-8 feet of pex line and 3 fittings.

While at different factories, I've questioned this valve, and stated what I had done. All have said similar statements. Well, we're required to do it this way, but there's really no reason why you can't do as you've done. I understand why they do it, but the valves are so cheap, and usually leak just as the OP's has. In most cases, this is in a wall, or under the sink. To the guy who doesn't know about these valves, he never checks them, and LOTS of damage can be done before it's caught. I got lucky on the one in the wall, and happened to see some dripping coming down into the basement. From that point on, I've always eliminated that potential and just removed them.