Black tank Vacuum Breaker location U320

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Black tank Vacuum Breaker location U320

October 30, 2023, 07:23:49 pm

So, am I to presume FT in their infinite (or in this case very finite ) wisdom placed the vacuum breaker in the side wall, behind the toilet? Coach is a U320 36 foot, toilet room driver's side opposite the lav/vanity.

Every time I use the black tank flush I get 2 or 3 drips coming from the 2 lines that go through the floor at about a 45 degree angle, into the cabinet behind the toilet and disappear into the wall...all in a ridiculously stupid and inaccessible fashion. Lines coming through the floor are inaccessible as more wisdom had FT place the drain and water lines from the washing machine as well as Aqua Hot heat exchanger lines and a couple electrical lines on top of the vacuum breaker lines at the bottom of the cabinet.

While I see no signs of protracted leakage on the floor plywood or anywhere else, the water has to be running down the lines and thus dripping on top of the black tank,....again only a couple drops upon each "first use" when flushing. This is one of those cases where "what you don't see, can hurt you" and I wish to remedy the issue.

I had to ask myself, why would FT not just run the lines up in the corner of the cabinet making it all visible and accessible? I plan to do just that, drill two new holes through the floor from the corner of the cabinet (verifying first no steel or other obstacles in the way) and locate a new vacuum breaker in the corner of the cabinet.

Anyway, looking for wisdom from the collective experience it my first assumption is correct about the current location and if there are other options as it must be above the top of the toilet bowl....

Thanks in advance for any input...

Bob

Re: Black tank Vacuum Breaker location U320

Reply #1 – October 30, 2023, 10:21:34 pm

Quote from: rusczyk56 – October 30, 2023, 07:23:49 pm

So, am I to presume FT in their infinite (or in this case very finite ) wisdom placed the vacuum breaker in the side wall, behind the toilet? Coach is a U320 36 foot, toilet room driver's side opposite the lav/vanity.

Every time I use the black tank flush I get 2 or 3 drips coming from the 2 lines that go through the floor at about a 45 degree angle, into the cabinet behind the toilet and disappear into the wall...all in a ridiculously stupid and inaccessible fashion. Lines coming through the floor are inaccessible as more wisdom had FT place the drain and water lines from the washing machine as well as Aqua Hot heat exchanger lines and a couple electrical lines on top of the vacuum breaker lines at the bottom of the cabinet.

While I see no signs of protracted leakage on the floor plywood or anywhere else, the water has to be running down the lines and thus dripping on top of the black tank,....again only a couple drops upon each "first use" when flushing. This is one of those cases where "what you don't see, can hurt you" and I wish to remedy the issue.

I had to ask myself, why would FT not just run the lines up in the corner of the cabinet making it all visible and accessible? I plan to do just that, drill two new holes through the floor from the corner of the cabinet (verifying first no steel or other obstacles in the way) and locate a new vacuum breaker in the corner of the cabinet.

Anyway, looking for wisdom from the collective experience it my first assumption is correct about the current location and if there are other options as it must be above the top of the toilet bowl....

Thanks in advance for any input...

Bob

To best of my knowledge no vacumn breaker on black lines, just vent to roof.

If I'm wrong I'm sure someone will have the facts.

Re: Black tank Vacuum Breaker location U320

Reply #2 – October 31, 2023, 08:06:27 am

There is a vacuum breaker on the black tank flush line. Mine is located behind the washing machine next to the air admittance valve for the washer drain line. It has to be higher than the highest point of the tank so in my case it's actually in a pretty logical location.

Re: Black tank Vacuum Breaker location U320

Reply #3 – October 31, 2023, 08:48:32 am

I guess I will have to break out my "proctoscope" (pun intended) and see what's under the pile of plumbing and wiring running on top of where the lines appear from the floor. Will also run the "probe" behind the washer and look. If it is behind the washer, now I have to rethink the cause as that would put another pair of 90s and horizontal run in the equation.....

Thanks for another bread crumb in my quest for enlightenment....

Bob

Re: Black tank Vacuum Breaker location U320

Reply #4 – October 31, 2023, 10:08:23 am

Quote from: Geodmann – October 31, 2023, 08:06:27 am

There is a vacuum breaker on the black tank flush line. Mine is located behind the washing machine next to the air admittance valve for the washer drain line. It has to be higher than the highest point of the tank so in my case it's actually in a pretty logical location.

Here are the 2 AAVs behind my washer (white valves in pic)

Re: Black tank Vacuum Breaker location U320

Reply #5 – October 31, 2023, 12:31:39 pm

Thanks but this is not what I am talking about. Those are vacuum reliefs for the drain line going to the grey tank.

What I am looking for is a back flow/vacuum break valve that is in the black tank flush line circuit (1/2 inch pex out and back). Routing would be from the flush inlet to a point higher than the top of the toilet bowl. At that point the back flow/vacuum device would exist and out the other side of the device would be a return line to the entry port at the top of the black tank.

The reason for the device (and it's "highest point" in the black system) is to eliminate the possibility of black tank contents making their way out of the port....or to a and water hose (no, nobody has ever connected a fresh hose to the flush....).

I am so paranoid that I have a black flush hose and a 6 foot stub hose with it's own backflow/vacuum breaker on the end away from the coach.

So, the question still exists, does anyone know if my assumption is correct......the thing is buried in the outside wall, behind the toilet. Current all road lead to that location. Wish I owned one of those fancy new wall scanners.

Standing by for more enlightenment.

Bob

Re: Black tank Vacuum Breaker location U320

Reply #6 – October 31, 2023, 08:06:00 pm

On our 2003 the vacuum breaker was under the kitchen counter behind the drawers under the stove.

Re: Black tank Vacuum Breaker location U320

Reply #7 – October 31, 2023, 10:53:19 pm

Quote from: red tractor – October 31, 2023, 08:06:00 pm

On our 2003 the vacuum breaker was under the kitchen counter behind the drawers under the stove.

Ditto

Re: Black tank Vacuum Breaker location U320

Reply #8 – November 01, 2023, 09:20:25 am

I think I have a vacuum breaker behind my toilet.
It's a thetford aria.

Re: Black tank Vacuum Breaker location U320

Reply #9 – November 01, 2023, 09:43:59 am

From the OP.... Thanks for the replies. Issue is the items under the sinks and behind the washing machine are not what I am looking for. Those are standard waste drain vacuum breaker that are in place to eliminate the need for each plumbing drain to have a vent pipe.

What I am looking for is a device that is in the black tank flush loop to prevent any possibility of back flow from the tank wash port on the tank to the external flush connection in the wet bay. The device is connected to the 1/2 inch PEX loop at a location higher than the top of the toilet bowl......it appears to be in the wall, behind the toilet. If you closely inspect (when you have your wet bay covers off), the port at the top of the tank, you will find 1/2 red pex that leaves the port and heads (in my case) towards the rear of the coach to meet up just adjacent to the water line to the toilet. Another line will parallel the black tank line back to the hose connection port on the wet bay panel. Where those two lines meet (somewhere in the wall) there is a backflow/vacuum breaker that prevents tank waste from syphoning or otherwise sloshing and exiting the port. Also allow the line to fully drain in both directions preventing mixing of street (yes, don't connect your fresh hose) water and tank "stuff".

Anyway, I have attached a photo of the device. I will find this bugger (or maybe not). But rest assured it's getting relocated to the cabinet behind the toilet. Like I said early on, all signs lead to the outside wall behind the toilet.

Now back to the hunt.... Thus ends the lesson!

Bob

Re: Black tank Vacuum Breaker location U320

Reply #10 – November 01, 2023, 09:54:58 am

Another picture of a "well placed" back flow preventer....

Re: Black tank Vacuum Breaker location U320

Reply #11 – November 01, 2023, 10:01:47 am

Quote from: rusczyk56 – November 01, 2023, 09:43:59 am

If you closely inspect (when you have your wet bay covers off), the port at the top of the tank, you will find 1/2 red pex that leaves the port and heads (in my case) towards the rear of the coach to meet up just adjacent to the water line to the toilet. Another line will parallel the black tank line back to the hose connection port on the wet bay panel. Where those two lines meet (somewhere in the wall) there is a backflow/vacuum breaker that prevents tank waste from syphoning or otherwise sloshing and exiting the port.

Interesting. In our '03, there was a red pex (hot water line) and white pex (cold water line) to the outdoor faucet. The line for the tank flush was white. It's the far right line in the attached photo

Re: Black tank Vacuum Breaker location U320

Reply #12 – November 01, 2023, 10:37:00 am

Now that I have seen this pic. of this back flow preventer I will add that if it is OEM it has been worked on by previous owner. The reason being is that the hose clamps and fittings you see in the pic. in reply 10 is aftermarket. OEM those years they used copper rings rather than those. I know that this isn't any help but if there was a previous failure it sure needs to be relocated.

Mike

Re: Black tank Vacuum Breaker location U320

Reply #13 – November 01, 2023, 11:38:33 am

Mystery location "CONFIRMED"....

Just spoke to the mother ship and it's confirmed, it is located in the wall, behind the toilet at or above top of bowl level. So now the question becomes, do I open the wall (it's behind a cabinet), replace in place and make a new access panel or do I relocated it to "in the cabinet" guarantying it will never leak again.....at least on my watch? Oh, did I say "I hate plumbing"....? Again, wish I had a wall scanner to determine if it is sufficiently above the toilet to get access to the fittings. I may just poke a small hole and stuff my "proctoscope" in to see before I decide the route to go.....

As to the comment about the wrong clamps in the photo on post 10, that was a picture from a SOB....

Hope this adventure (so far) has been a learning experience for the collective. Will keep all posted as to the process to a cure and outcome.

Bob

Re: Black tank Vacuum Breaker location U320

Reply #14 – November 01, 2023, 02:14:13 pm

Quote from: rusczyk56 – November 01, 2023, 11:38:33 am

Mystery location "CONFIRMED"....

Just spoke to the mother ship and it's confirmed, it is located in the wall, behind the toilet at or above top of bowl level. So now the question becomes, do I open the wall (it's behind a cabinet), replace in place and make a new access panel or do I relocated it to "in the cabinet" guarantying it will never leak again.....at least on my watch?

Have you checked the innards of the cabinet to see if the cabinet back is removable? Many of them are built that way (certainly over the head of the bed and over windshield/D/P seat cabinets are). You may need to "dig" in the corners of the cabinet bottom/floor if they're carpet/ozite-lined for the Robertson screws to remove the bottom panel, then check corners - especially upper ones - of the cabinet back panel (all of this inside the cabinet) for additional screws. Foretravel usually gives you the ability to remove the interior back panels with a little disassembly.

Re: Black tank Vacuum Breaker location U320

Reply #15 – November 01, 2023, 03:16:19 pm

I've found that a small rare earth magnet is helpful for finding the screw heads buried in the ozite.

Re: Black tank Vacuum Breaker location U320

Reply #16 – November 01, 2023, 03:44:40 pm

OP Here.

The cabinet in question is basically a "front" with doors and a top. It is screwed to the side walls of the toilet room. The back of the cabinet is a wall panel that ultimately extend beyond the cabinet. The only way in is with an ax, if you get my drift.

Plan is to carefully drill a hole saw with a 1 inch hole that will allow me to insert my proctoscope and take a peek. If my discovery is "positive", I will then map a minimal area to cut open and replace the bugger. Hoping to find it higher than the toilet with threaded fittings......."Hope springs eternal".

Will keep the collective posted....

Re: Black tank Vacuum Breaker location U320

Reply #17 – November 01, 2023, 10:14:43 pm

How about a pictures of area. I far away then closer up.

Re: Black tank Vacuum Breaker location U320

Reply #18 – November 02, 2023, 11:35:30 am

Just thinking: if you could warm up the black tank contents with hot water and wait a few minutes or longer it may be visible with an infrared camera. Particularly if it is against the paneling, even a digital thermometer may show a temperature differential on the wall.
Scan the wall first, heat up the tank and scan the wall again for a change in temp .

Re: Black tank Vacuum Breaker location U320

Reply #19 – November 08, 2023, 07:11:08 pm

News Flash....Update....

Well, nobody, even the "mother ship" was correct with the location of the backflow/vacuum breaker for the black tank flush on my coach.

Scanned the wall behind the toilet, nothing! Drilled a hole for my proctoscope and found some really nice closed cell foam, allowing me to confirm the reading of the scanner. Ran a coat hanger down the wall...more nothing but foam.

So with this I temporarily moved onto my next project, replacing the electric water valves on the Splendide....thus requiring the removal of said "unit" and then chasing of the power cord and water line connections.... What's that Christmas song?...."Over the river and through the woods". Chase the connections to under the bottom drawer of the "dresser" in the bedroom....and there they were.

While working to free the water lines from under the washer compartment floor I decide to pull the other three drawers to improve access for my body......and as Gomer Pile would say "G-o-o-o-ll-e-e e"....there it is. Stuffed in the outside corner, behind a short drawer glide support wall. Almost had to "Gibbs Slap" myself back to my senses as I processed the insanity of running the black tank flush lines further back in the coach, buried under a drain line and a host of other "stuff" and doing their best to hide it....short of putting it in the engine bay.

Well, now that opens a new set of opportunities for frustration as it would be impossible for my "drip" to originate "there" and make its way to the end of the elbow in the wet bay. I "suspect" (though physics and logic tell me otherwise), the drip is actually at the elbow connection. I will be wrapping both lines with blue shop towel material (greatest thing since sliced bread to find water) in order to see if it originates from above or at the joint......Hope springs eternal.

More FT logic and physics defying fun is discovered with the Splendide removal. The dryer exhaust line to the wall is a piece of 3 inch ABS that is literally pinned against the back of the machine with putty (like Mortite) packed around the pipe at the outlet of the machine. I won't go into the thoughts I had about this.... BUT, my real question was how did they do that as there is absolutely no physical access to the rear of the machine when in place..... but I digress.

Sorry for the "tome" but hopefully someone will gain a grain of knowledge from this near "Indiana Jones" expedition.

I will post some pictures lest some other poor, unsuspecting owner travels the same path!

Here endith the "revelation"....

Bob

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