Community Forums

JETJDM79 · 07-05-2016, 03:56 PM

We have a 2016 DSDP 4312. We do a lot of dry camping so fresh water capacity is very important to us and one of the reasons we purchased a new coach. I had requested a larger capacity fresh water tank and it was denied. I wasn't surprised and figured the reengineer wouldn't be easy plus weight issues...

I have been disappointed that on our first 2 trips, I haven't been able to successfully get to our destination without losing 20-30 gallons of fresh water. Through our travels the overflow is creating a siphon from what I can tell. I am assuming this isn't the "normal" and hope there's a solution. We have friends that have a 2013 DSDP and they have a similar issue but fresh water capacity is not as big of a deal for them. They say, they fill to "full" and when they reach their destination they are always at 2/3 capacity.

I appreciate the time, consideration and any recommendations or solutions!

Thank you,

Justin and Laura McClure
2016 DSDP 4312
Harrisburg, PA

Sky_Boss · 07-05-2016, 03:59 PM

Take a look at this thread I just started about the time you posted.

sdennislee · 07-05-2016, 04:02 PM

Is it actually draining through the overflow? I have seen 2 coaches drain through the siphon line (winterizing line) from the onboard pump. The issue was the pump valves were positioned to suction the pink stuff.

DAJO · 07-05-2016, 04:37 PM

You can modify your tank like Ski Boss did, it will ensure that you arrive with a full tank. It will still siphon when overfilled like he explained. The mod does stop water loss on the road. I have modified three Newmars with complete success. One of the stupid things Newmar does and will not change after all these years.

racer0624 · 07-05-2016, 04:46 PM

Justin,
I modified my overflow hose per skyboss's example. My configuration was a little different but the same principal. I can now fill 'er up and arrive to our dry camping spot with a full tank whereas before I could count on loosing around 15 gal.

JETJDM79 · 07-05-2016, 05:14 PM

Quote:

Originally Posted by Sky_Boss

Take a look at this thread I just started about the time you posted.

Thank you sir! Great info!

JETJDM79 · 07-05-2016, 05:16 PM

Quote:

Originally Posted by sdennislee

Is it actually draining through the overflow? I have seen 2 coaches drain through the siphon line (winterizing line) from the onboard pump. The issue was the pump valves were positioned to suction the pink stuff.

I am pretty sure it's the overflow. I did factory delivery and we checked all valves were properly positioned. But, I am going to double check! Thanks for responding!

JETJDM79 · 07-05-2016, 05:16 PM

Quote:

Originally Posted by DAJO

You can modify your tank like Ski Boss did, it will ensure that you arrive with a full tank. It will still siphon when overfilled like he explained. The mod does stop water loss on the road. I have modified three Newmars with complete success. One of the stupid things Newmar does and will not change after all these years.

Thanks for the response!

JETJDM79 · 07-05-2016, 05:17 PM

Quote:

Originally Posted by racer0624

Justin,

I modified my overflow hose per skyboss's example. My configuration was a little different but the same principal. I can now fill 'er up and arrive to our dry camping spot with a full tank whereas before I could count on loosing around 15 gal.

Great to know and thanks for the response!

MisterT · 07-05-2016, 05:28 PM

your overflow question has got me to thinking on mine: I've noticed this also several times after filling the tank close to full - we leave a great deal of water along a 'wet line' behind the coach as we are leaving. I suppose this is due to sloshing of the tank while leaving, with the overflow slosh leaving out the overflow tubes(2).

I'm thinking that the overflow tubes are for that rare time when you 'forget' that you are filling the tank, but the other 99.987% of the time they only allow for air into the water tank, and possibly 'other' critters. Now, maybe you need air intake when the pump ask for water, but the rest of the time it seems counter-intuitive...

Is there a simple something to insert into the overflow tubes that would allow the air intake, when needed, but keep the water from just sloshing out?

Sky_Boss · 07-05-2016, 08:16 PM

Quote:

Originally Posted by MisterT

...
Is there a simple something to insert into the overflow tubes that would allow the air intake, when needed, but keep the water from just sloshing out?

On my coach there is a rubber duck bill at the exit of the drain hose that lets air and water out and closes up to keep other stuff out. It isn't capable of blocking overflow water and I don't think you would want that anyway.

DAJO · 07-06-2016, 07:33 AM

There is also a check valve that allows air to enter, it is in the picture of other thread a few inches behind the overflow opening (black cap). The check valve can also be raised up by adding a threaded extension.

Sky_Boss · 07-06-2016, 08:14 AM

Quote:

Originally Posted by DAJO

There is also a check valve that allows air to enter, it is in the picture of other thread a few inches behind the overflow opening (black cap). The check valve can also be raised up by adding a threaded extension.

That valve is also known as an air admittance valve and does as you say to allow air in as the tank is emptied. It is water tight if working properly so adding an extension to it probably doesn't do anything regarding siphoning.

If you are able to see the tanks as you fill the fresh water to the point of overflow you shouldn't see any water from that valve. If so, you have a problem and need to replace it. They are readily available at any home supply store like Lowes.