how does the drain work in a pop up sink

capslock118

Member
Jun 25, 2012
25
my pop up - a 1999 viking 1706 - says it has a trap to prevent odors.

anyways, my sink is filled half-way with water and nothing is coming out of the drain outside.

i should say it did drain a little bit once while i was testing it, but nothing since.

is there some kind of lever somewhere? i've felt around, looked under the sink, can't find anything obvious.

i'm thinking that maybe the drain is clogged, but i don't know for sure.

thoughts?
 

CJohns

Member
Jun 6, 2012
14
My sink drains through a hose directly outside. I don't know if this is standard or not but if I had this problem, I'd probably try to run a snake or something like that down the drain to see where it was plugged up. And, if this did not work, I might try putting a snake or air compressor on the drain exit and blowing the other way to push whatever it was back up and out the sink.
 

papachaz

Super Active Member
Jun 26, 2011
2,821
the 3 different pups i've had, all had a flexible hose connected to the drain, and i have seen it get pinched or kinked and slow down the flow, maybe that's it?
 

bondebond

Super Active Member
Aug 14, 2008
2,330
For the purposes of diagnosing this, I would (at home) set up the PUP and remove the drain cap on the outside wall, but do NOT connect anything to it. Poor some clean water in the sink and see if it drains.

If it does drain, then the problem likely exists outside. If it does not drain, your problem is under the sink.

If it does not drain, there are a couple of obvious targets: being clogged is one - clean out the drain, the trap, the hose, etc. If it was clogging up on me, I would be tempted to disassemble the entire works and visually inspect to make sure that there isn't some plastic barb that is catching items, trapping them and thereby causing a clog. Reassemble and test.

The second cause that comes to mind is that there is often too much slack in the flexible hose from the sink base to the wall where it exists the PUP. Since there is probably a p-trap at the sink, this drop in the hose causes another trap to be formed and can cause slow draining as well. This happened on my first PUP. I disconnected the hose, cut some excess off, reconnected and was much happier afterwards.

If it is draining properly without anything connected on the outside. There's a whole bunch of "it depends" on how you have your gray water tank set up. Ideally, the drain hose connected to the fitting on the exterior wall and then to your gray water tank should be a straight shot (relatively speaking) without dipping below where the hose connects to the gray water tank to drain the water into. If you have loops of garden hose, or even a bit of it dips below the connection point on the gray water tank, you've created another trap, and it will not flow well.

Now, imagine if the situation is that there is a slight dip from the sink drain to the wall AND there's a slight dip from the wall to the gray water tank - that's tough to get anything to drain.

That's why I say break it down to Inside vs. Outside and narrow down the troubleshooting areas.
 

Unstable_Tripod

Well, there's your problem!
May 20, 2008
14,278
Seattle, Washington
If the PUP has a flip-over galley I would not shorten the flexible drain hose too much. Be sure that there is enough left to reach when the galley is turned over.

If you don't have a flip-over galley, never mind.
 

solpushcart

Member
Aug 2, 2011
23
Here's what I'm going to do this weekend. Since all sinks need some sort of vent to help get things moving, and if your pup is like mine, there isn't one under there. So, since the drain line is flexible, I will figure out the best place to cut the line and install a vent. Similar to those you see connected to your dishwasher. It will of course have to be mounted to the underside of the sink so it stays as high up as possible.

This of course if you know there is no clog.
 

Dubbya

Wherever you go, there you are...
Aug 2, 2011
6,158
Steinbach, MB
The deal with the stock drain hose assembly is that the "built in vent" is located at the bottom of the big white plastic drain cup that attaches to the sink strainer. If you remove the tiny thumb screw sticking out the bottom of the drain cup, you'll see how it works.

It sorta/kinda works but it can take ages for a full sink to drain through 20' of 1/2" or 5/8" garden hose.

The hose itself is 3/4" hose but the barbed ends on the drain cup and the gray water drain fitting are only 1/2". It's a small sink but you'll never get that thing to drain worth a fiddler's (expletive) unless you change the drain and drain hose out with something a little more substantial.

Adding a vent is a great idea. You can take the low-dough approach and use a "Y" garden hose connector with some PVC pipe on the outside of the pup wall or you can install a (slicker than chicken snot) cheater vent on the inside.

Check out my sink to sewer drain mod for some ideas.
http://www.popupportal.com/index.php?topic=61205.0
 

Unstable_Tripod

Well, there's your problem!
May 20, 2008
14,278
Seattle, Washington
I find it interesting that so many people have vent problems with their sinks, I guess the arrangement must be different than what I had on my Yuma or have on my TrailManor. I have never had any difficulty with a sink drain and never needed to do a vent mod.
 

Dubbya

Wherever you go, there you are...
Aug 2, 2011
6,158
Steinbach, MB
Unstable_Tripod said:
I find it interesting that so many people have vent problems with their sinks, I guess the arrangement must be different than what I had on my Yuma or have on my TrailManor. I have never had any difficulty with a sink drain and never needed to do a vent mod.
There's a little "Tim Taylor" in the heart of every modder. Sometimes the "cool factor" outweighs need, common sense and fiscal responsibility! LOL!
 

raymonk

Active Member
May 13, 2011
475
On my 96 1706 ST Viking, the drain assembly is just a corrugated hose that terminates at a hose connector on the outside of the pop up. It also has a cap on the end, to prevent critters from crawling back in. Viking drains run a little slow because the diameter of the outlet is made to connect to a hose that can easily clog up. Your drain assembly might be a little clogged somewhere, but it isn't too hard to flip the galley over and disconnect the hoses to clean it out. Are you sure that your drain hose isn't kinked? I never tried it, but I think that a using water pressure from a garden hose might free up whatever is stuck, using a towel to cover the nozzle to prevent back pressure. Could be the fastest way to unclog it.
 

Yukon Jake

Member
Mar 1, 2012
67
I have found that just the flipping the flip-over galley back and forth, 15 to 30 degrees a few times drains the sink pretty quickly. I pretty much have to do this after each use of the sink.
 

Full Circle

Greely, Ontario, Canada
Apr 4, 2009
1,226
Greely, Ontario
Hi everyone, been a while since posting. I saw this post and since the pup is up and we're camping i figured i'd snap a shot of my setup. In the couple of different pups we've had with a flip over sink, its always been the length of drainhose that causes the issue, here's how i solved it...

4ac6a483-f869-9169.jpg


As you can hopefully see, i used a picture hook into the framing and a piece of rope to help slope the drain line, never a draining issue with this done. I just have to remember to unhook the rope before flipping the galley back over.

Ad


Sent from my HTC EVO 3D
 

Nanapoppypops

Active Member
Mar 30, 2019
306
Lake Placid, NY
My sink drains through a hose directly outside. I don't know if this is standard or not but if I had this problem, I'd probably try to run a snake or something like that down the drain to see where it was plugged up. And, if this did not work, I might try putting a snake or air compressor on the drain exit and blowing the other way to push whatever it was back up and out the sink.
Does the sink have to be connected to the hose and container as soon as you start camping? Sorry for the dumb wuestion
 

theseus

Living the Darkside...
Silver Supporting Member
Feb 6, 2007
3,553
Centerville, OH
Does the sink have to be connected to the hose and container as soon as you start camping? Sorry for the dumb wuestion
If it isn’t water will run down the side of the camper on to the ground. Some campsites require that you collect your drain water to dispose off it properly.
 

roybraddy

Super Active Member
Mar 23, 2016
2,393
King George, Virginia
I just noticed this is a 2012 post haha... I just saw BONDEBOND from Arkansas one of my old friends from the past made a comment... I haven't heard from him in years haha...

This is what I do for collecting sink water... When one tank fills up I switch to the second tank and haul the first tank off... Some places will allow you to pour this dirty water on tree trunks... I would do this away from the camp site however to keep any smell from building up...

eoY03.jpg

Roy's imagine

I carry one of those folding two wheel carts on my camping trips as 7-gal of water is pretty heavy haha...

Roy Ken
SoQ6BfGm.jpg
 

Nanapoppypops

Active Member
Mar 30, 2019
306
Lake Placid, NY
I just noticed this is a 2012 post haha... I just saw BONDEBOND from Arkansas one of my old friends from the past made a comment... I haven't heard from him in years haha...

This is what I do for collecting sink water... When one tank fills up I switch to the second tank and haul the first tank off... Some places will allow you to pour this dirty water on tree trunks... I would do this away from the camp site however to keep any smell from building up...

eoY03.jpg

Roy's imagine

I carry one of those folding two wheel carts on my camping trips as 7-gal of water is pretty heavy haha...

Roy Ken
SoQ6BfGm.jpg
Thanks for pics and advice
 




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