Black tank flush line

[Rabbit]

The water going to the black tank flush first passes through the vacuum breaker, then goes to flusher inside the tank.

[Riverbug]

Guess I better be more careful in the future. I've been running my flush at full pressure. Never had an issue but never gave it much thought either so better safe than sorry.

[Redapple63]

Guess I better be more careful in the future. I've been running my flush at full pressure. Never had an issue but never gave it much thought either so better safe than sorry.

Yea, that vacuum breaker will be the first to go under pressure.

Bill

[Always Learning]

Guess I better be more careful in the future. I've been running my flush at full pressure. Never had an issue but never gave it much thought either so better safe than sorry.

I always measure the pressure before connecting my black tank flush using a hose bib water pressure gauge. If it is under 50 or 60 I do not use a pressure regulator, if over I use a regulator. I never thought about the vacuum breaker failing, I was concerned that high pressure might blow the spray nozzle off the inside of the tank. I have seen up to 120psi on dump station and campground water lines. The dump station we are using now has 100psi when no one is washing a boat at the nearby boat wash.

[Bluffrat361]

Responding just to pass on info for a 2021 transcend xplor 265BH. So far I have pulled the actual tank flush connection. The line goes under the sink like y’all said, to a vac breaker, then down to the under carriage. I don’t see any wood damage so that is a good sign. I’m thinking the leak is right at the black tank. I’m gonna put a small endoscope I’m gonna put into the line tomorrow and will keep this topic updated for future reference. Thank y’all for the help so far

[Riverbug]

I always measure the pressure before connecting my black tank flush using a hose bib water pressure gauge. If it is under 50 or 60 I do not use a pressure regulator, if over I use a regulator. I never thought about the vacuum breaker failing, I was concerned that high pressure might blow the spray nozzle off the inside of the tank. I have seen up to 120psi on dump station and campground water lines. The dump station we are using now has 100psi when no one is washing a boat at the nearby boat wash.

That's a good idea. I'll start using my gauge for a quick check too going forward.

[Redapple63]

Responding just to pass on info for a 2021 transcend xplor 265BH. So far I have pulled the actual tank flush connection. The line goes under the sink like y’all said, to a vac breaker, then down to the under carriage. I don’t see any wood damage so that is a good sign. I’m thinking the leak is right at the black tank. I’m gonna put a small endoscope I’m gonna put into the line tomorrow and will keep this topic updated for future reference. Thank y’all for the help so far

Thanks for the update.

Bill

[Bluffrat361]

Ok so I followed the line from the vacuum breaker to the black tank. I found where the line ties into the side of the black tank. Where I have it marked is the approximate area where the black tank flush goes into the black tank. I put an endoscope on the tie in and had one of my kids turn the water hose on. I then I had them kink the hose to build up pressure and let it go all at once to mimic higher pressure. Good news is I don’t see anything leaking. So I’m thinking it only leaks when it sees high pressure. I’ll attach a pic of where it ties in. I’ll also attach a video of the tie in when I figure how to do that. Thank y’all for the help

[Bluffrat361]

Here is the footage of when I turned the water on to the black tank flush

https://vimeo.com/748596980

[mmontalvojr]

I had a leak when I flushed my black tank the first trip this year. I spoke to the manufacturer of the water inlet and the check valve and he said the first thing you should check is the fitting on the water lines. Sure enough, mine had come a little loose. After I snugged it up, everything has been fine.

He explained that you should periodically check and tighten your water line fittings at the sinks, check valve, everything you can reach. Those trailers bounce around like crazy going down the road, so it makes sense that things can work themselves loose over time.