Jump to content

Black Tank Flush Backflow Valve


Recommended Posts

  • Moderators

Black tank dumping/flushing has become a challenge lately.  Flow through the flush has slowed to a trickle.  I removed the valve next to the black tank and there is a rubber ring that was quite deformed and was half under and half over the valve.  I tried to reposition it then reinstalled it but there is no difference.  It’s an annoyance at a FHU site (30 minutes to get to 50%) but is unacceptable at a dump station.  I opened a trouble ticked with Oliver and it’s $58 for a new valve.  Seems high to me.  Does anyone know if this is something that can be purchased at a HD or Lowes or plumbing supply store?  I could fix it while on the road and not have to wait until we get home.  Here’s a picture of what I’m talking about.  It’s the gray part next to the tank.  Mike

 

8DFE743D-EDCE-4013-AECD-FFE6BDE9957A.jpeg

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

  • Moderators

As far as I know, this is nothing more than a anti-siphon check valve.  If that is correct then virtually any check valve of that sort would work as long as the length and the fittings on the end are adaptable.

Of course another thing you can do would be to cobble a non-anti-siphon piece of pipe in there until you get home where you can search better for a "better" solution.  Certainly you will be very careful with any cobbled together solution and I'd guess that it would be technically illegal in many places.

Bill

  • Like 1

2017 Ford F150 Lariat 3.5EB FX4 Max Towing 2016 Oliver Elite II - Hull #117 "Twist"

Link to comment
Share on other sites

Take it apart again, go to an Ace Hardware store and they should be able to match up the seal for a dollar or two at most. Buy a spare for your kit. Alternatively, if you are near a larger city, an RV parts supply store … If that doesn’t work, ask Oliver for the make and part number of the valve, you most likely can find it at an online vendor to at least see if their price is acceptable (it does seem very excessive unless it includes overnight shipping and hand delivery to your campsite 😬). I suspect it is a special RV part, most common types have female threads

D5785D04-5AC3-4466-B5A3-08E147EE2790.thumb.jpeg.e2504dd7d2dca64ee43722808ec94c1b.jpeg

Take pics please. Good luck. What a sh**y project😬

John Davies

Spokane WA

  • Like 3

"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags, Safari snorkel.

Link to comment
Share on other sites

15 hours ago, Mike and Carol said:

Does anyone know if this is something that can be purchased at a HD or Lowes or plumbing supply store? 

It looks like an ordinary 1/2" MPT x 1/2" MPT check valve to me.  Pull the part and verify pipe diameter to be sure.  But, I'll bet the Pex pipe that connects to the valve is 1/2", so odds are high that the fitting is 1/2".

A brass version offered by Valterra (which would be an upgrade from the plastic one Oliver installed)  is available from Amazon for under $10:

https://www.amazon.com/Valterra-P23415LF-Lead-Free-Check-Valve/dp/B00HJ6P0Z8/ref=sr_1_5?gclid=CjwKCAjwwL6aBhBlEiwADycBICgly1OwtJDY5Q9FclIA3jCEEmcXbufHEPlR1A_rkK51r41DjwB-PRoCqMkQAvD_BwE&hvadid=616862894778&hvdev=c&hvlocphy=9029558&hvnetw=g&hvqmt=b&hvrand=2988426038172399198&hvtargid=kwd-315243267828&hydadcr=24633_13611805&keywords=1%2F2+inch+check+valves&qid=1666189161&qu=eyJxc2MiOiIyLjMwIiwicXNhIjoiMS44NSIsInFzcCI6IjEuNDYifQ%3D%3D&sr=8-5

Camping World sells the same fitting:

https://www.campingworld.com/12-brass-check-valve-x-mpt-95194.html

You may be able to find a Camping World, or even just an RV supply store, on your route that would have it in stock.

Good luck!

  • Like 2

 

Hull #1291

Central Idaho

2022 Elite II

Tow Vehicle:  2019 Tundra Double Cab 4x4, 5.7L with tow package

spacer.png

 

Link to comment
Share on other sites

Some of those flushers come with a check valve built into the spray nozzle itself ,making an external one redundant. You should be able to see if yours does  by looking into the connection fitting. If it does, just take some needle nose pliers and break the guts out of that gray valve and use it as a straight nipple. 

  • Like 1
Link to comment
Share on other sites

  • Moderators

Thanks all.  We just arrived at our campground in Louisiana, far from any civilization and with barely a bar of cell coverage.  Tomorrow we’re in Waco for a couple of days and I will work on it then.  If I can’t find one there, I’ll order one of the top two in JD’s Amazon picture above.  Mike

  • Like 2

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

  • Moderators
53 minutes ago, Mainiac said:

If, in the mean time, you want to flush the tank, you could just pour a bucket of fresh water down the toilet? Fix it at you leasure?

I’ll either do that or put a hose through the bath window.  I’ll probably fix it when we get home this weekend.

  • Thanks 1
  • Like 1

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

  • 2 weeks later...
  • Moderators

Just to close this out….

 I ordered a replacement Thetford valve from Amazon, $8.  It’s one in the picture in John’s post above.  There are actually two valves, one inside the tank (white) which comes out when unscrewed and the gray one which is the one that went bad.  I put on new thread tape and reinstalled and we’re back in business.  The replacement is a little shorter than the original, but fit with no problem.  I’ve seen some pictures of what is in other trailers and they are not all the same.

 

Here’s the assembly and the new part.  The white part on the right is the second valve that screws into the tank.

A834F376-7718-40E9-BCD5-617DEC267348.thumb.jpeg.e5e80ab670375778860522dc4716cb03.jpeg

 

The new black valve replaced the old gray.

64C89EC2-702B-4A86-9AE7-DD02DF2726AA.thumb.jpeg.6ed38c60163269086cd9c5f4b774b7e4.jpeg

 

Here it is back in place.

D57EF3D9-A12A-4425-95B1-F67D6F7289F9.thumb.jpeg.caaaf52fea366b297dba4e566de744ad.jpeg

  • Thanks 1
  • Like 6

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

17 hours ago, Mike and Carol said:

Just to close this out….

 I ordered a replacement Thetford valve from Amazon, $8.  It’s one in the picture in John’s post above.  There are actually two valves, one inside the tank (white) which comes out when unscrewed and the gray one which is the one that went bad.  I put on new thread tape and reinstalled and we’re back in business.  The replacement is a little shorter than the original, but fit with no problem.  I’ve seen some pictures of what is in other trailers and they are not all the same.

 

Here’s the assembly and the new part.  The white part on the right is the second valve that screws into the tank.

A834F376-7718-40E9-BCD5-617DEC267348.thumb.jpeg.e5e80ab670375778860522dc4716cb03.jpeg

 

The new black valve replaced the old gray.

64C89EC2-702B-4A86-9AE7-DD02DF2726AA.thumb.jpeg.6ed38c60163269086cd9c5f4b774b7e4.jpeg

 

Here it is back in place.

D57EF3D9-A12A-4425-95B1-F67D6F7289F9.thumb.jpeg.caaaf52fea366b297dba4e566de744ad.jpeg

Mike,

Nice job!

  • Thanks 1

Tundra LE2

 

Link to comment
Share on other sites

  • Moderators
8 hours ago, Geronimo John said:

Just wondering:  For those of us that have a isolation valve, why do we need a check valve?    

Good question.  Also, why do I have two check valves, one connected to the other?  I thought about just eliminating the bad one (gray in the picture) and just going straight to the one that screws into the tank (white one).

  • Like 1

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

The white one isn’t a check valve. It is a spray nozzle. The idea is to blast all around the walls of the tank, to get rid of the gunk that sticks there, not just fill it up.

Check valves provide one way flow protection. You do not want black water going back into the fresh water supply. That “normally” would never happen, but if something happened in the fresh supply system, it could possibly syphon  back and contaminate it. The RV codes require a functioning check valve here (complete separation of fresh and sewage systems). Just like residential code requires check valves when you connect up an irrigation system to city water.

The other check valves in the back of the trailer are installed to prevent your pressurized water from simply going the wrong way. It is all about traffic control, like one way streets. 

John Davies

Spokane WA

  • Thanks 1
  • Like 5

"Mouse":  2017 Legacy Elite II NARV (Not An RV) Two Beds, Hull Number 218, See my HOW TO threads: https://olivertraveltrailers.com/topic/john-e-davies-how-to-threads-and-tech-articles-links/

Tow Vehicle: 2013 Land Cruiser 200, 33" LT tires, airbags, Safari snorkel.

Link to comment
Share on other sites

16 hours ago, Mike and Carol said:

I’ve seen some pictures of what is in other trailers and they are not all the same.

Apparently Oliver has changed this arrangement up more than once.   My trailer does not  have any check valves on the black  tank, just a simple brass elbow, possibly connected to a spray nozzle.  Connected to it is a white pex line  that goes up under the sink in the head, attached to a brass vacuum break valve.  I think it also has a brass check valve.   Then it loops back down to the flush inlet on the side, also a simple brass elbow.   Since I have a Natures Head, this line is not used.   The heavy brass valves were  not secured, and rattled around under the sink.   I removed all of it and capped off the elbows, stored it away.  While I was under the sink, I easily removed the toilet water supply line and valve, also not used.   Now I do not have to winterize that  line.  I don’t have a pic of the vacuum breaker valve but I can get one if you are interested.    This vacuum break arrangement is not shown in the 2021 or 2022 Elite II owners manual plumbing diagram,  but it is shown in the Elite diagram.

3CFB0444-4737-428C-9A81-F4AD594D89FD.jpeg

521D40B7-5AD9-4E85-89F8-463103B59896.jpeg

EAA53714-1911-4BFB-BE86-D4B03668A23C.jpeg

  • Like 2

“Ramble” - 2021 Legacy Elite II #797;  2020 Ford F-250

Link to comment
Share on other sites

2 hours ago, Mike and Carol said:

Good question.  Also, why do I have two check valves, one connected to the other?  I thought about just eliminating the bad one (gray in the picture) and just going straight to the one that screws into the tank (white one).

Two check valves and initially a shutoff valve. Someone wanted to be absolutely sure? More likely just a case of not really understanding what was what. At least they eventually  eliminated the shutoff valve. The hookup kit for the No-Fuss flusher doesn't include much more than a garden hose inlet fitting and connection hose fittings. Valterra must figure the integrated check valve is enough to satisfy RVIA requirements.

  • Like 2
Link to comment
Share on other sites

  • Moderators
5 hours ago, John E Davies said:

The white one isn’t a check valve. It is a spray nozzle. The idea is to blast all around the walls of the tank, to get rid of the gunk that sticks there, not just fill it up.

When I looked at both valves when I disassembled them, they both looked very similar.  I assumed they were both check valves.  It makes sense that the one that screws into the tank is a spray.  Mike

  • Like 3

Texas Hill Country | Elite II #135 | Ram 2500 6.7L

ALAZARCACOFLGAIDILKSKYLAMDMSMOMTNENVNMNYNCNDOHOKSCSDTNTXUTVAWVWYsm.jpgALAZARCACOCTDEFLGAIDILINIAKSKYLAMEMDMAMS

Link to comment
Share on other sites

13 hours ago, bhncb said:

At least they eventually  eliminated the shutoff valve.

Personally, I prefer a valve I can close off vs. one or two check valves that can fail when they want to so as to cause the most adverse consequences.

But then I NEVER leave a pressure hose hooked up to our OE2 more than temporarily filling the fresh water tank, or flushing the black tank.  My rationale is that I have zero confidence that the pressure water system pressure for all the systems I load water from are at a level that will not damage my trailer.  With or without a pressure regulator.

Yes, that makes me run my fresh water pump a lot.  But when it fails, I for sure know where to look.    Just my two cents.

GJ

  • Like 3

Tug:  2019 F-150 SuperCrew Lariat, 3.5L EcoBoost, Max Trailer Tow, FX-4, 4X4, Rear Locker

image.jpeg.9633acdfb75740f0fd358e1a5118f105.jpeg

 

 

 

 

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...