Connecting Gray Water Drains

[Sherwolfe]

So when we had our 2015 Cougar 28RLSWE the rear galley gray tank had a drain valve that when opened allowed the gray tank to drain into the main dump for the sewer hose. This was accomplished by having the rear tank plumbed to the main sewer dump which also had the shower gray tank and the black tank, each on separate dump valves. So what I'm trying to explain is both gray tanks and the black tank all drained out the main sewer hose, each on a separate valve.

Now, since we upgraded last year to a 2019 Cougar 29RLDWE to enjoy the larger bedroom for some reason Keystone decided to have a separate dump valve and sewer connection for the galley gray tank. This now requires two sewer hoses connected with a Y connection, OR, move the sewer hose from the main dump to the galley gray tank to dump the tank. What a pain in the, well, you know.

Has anyone dropped the coreplastic from the trailer and run a connection drain line from the rear galley gray tank to the single dump sewer connection, thus allowing all three tanks to drain out one sewer connection? I do recall on my 2015 Cougar that the smaller line connecting the rear tank to the main drain didn't have much of a slope or drop which did cause the rear tank to drain slow. But a slow drain is much better than having to connect two hoses to a Y connection. I also understand that with a slow drain you run the risk of having debris build up in the tank, but I would add some Happy Camper to the galley tank every other trip to help keep much from building up.

Not sure if this would be worth the effort of if it is even doable but thought I would toss the idea out there to some of you and see what y'all think.

[sourdough]

You describe one of the things I avoid when looking at a prospective new trailer. If it has dual sewer outlets it's on to something else - but there seem to be quite a few of them anymore.

From what I've seen everyone just throws out the double slinkys, hooks them to the Y and goes at it - some have some pretty elaborate setups.

My concern about trying to modify the existing setup to one outlet would be the same as yours along with other considerations. Also, although it is easy to rationalize the 2nd sewer outlet as Keystone being cheap there could well be other usage considerations to worry about - and I've tried using "slow moving" drains and ended up having to replace it all after so much sludge built up in them. Combine those potential issues with the trouble, expense and "what if it doesn't work" considerations and I think I'd just build me that elaborate slinky system.

[chuckster57]

The issue is most likely the inability to get the needed “slope” for proper draining with the framework underneath. Is it worth it to attempt rerouting the drain? Only you can decide, but I had seperate drains on my ‘97 Jayco, and you had to reach under the slide to the frame for the back one. I moved my single hose each time for the 13 1/2 years I owned it.

[travelin texans]

I'm guessing that with one tank in the rear & the others in front of the axles it's not able to be connected & clear over the axles with any slope.
That's the drawback to a lot of the newer floorplans with sinks &/or toilets on each end of the RVs.
As the old saying goes "sh## rolls downhill", I'm sure this is why they're plumbed the way they are.

[Sherwolfe]

Sourdough, I agree with just moving on, however this floor plan really appealed to us with the bedroom having the slide out and extra space. We have stayed at a few places where they actually have two sewer hook ups which works nice.

[Sherwolfe]

Originally Posted by chuckster57

The issue is most likely the inability to get the needed “slope” for proper draining with the framework underneath. Is it worth it to attempt rerouting the drain? Only you can decide, but I had seperate drains on my ‘97 Jayco, and you had to reach under the slide to the frame for the back one. I moved my single hose each time for the 13 1/2 years I owned it.

Chuckster57, overall I may just leave it and continue to work with it. Like you say at the end of the day is it really worth it. I just wanted to check with some of the experience on this forum as to solutions.

[Sherwolfe]

Originally Posted by travelin texans

I'm guessing that with one tank in the rear & the others in front of the axles it's not able to be connected & clear over the axles with any slope.
That's the drawback to a lot of the newer floorplans with sinks &/or toilets on each end of the RVs.
As the old saying goes "sh## rolls downhill", I'm sure this is why they're plumbed the way they are.

Travelin Texans, so seems like the wife has found a solution, she just explained that if she didn't cook or wash any dishes then the problem would be solved !!! So given this new concept and the fact that overall it likely would actually create more problems than just working with it I suppose we will just enjoy our camping trips with everything as is.

[JRTJH]

I would consider buying a twist-on 90 degree elbow sewer fitting (3" connection/1.5" reduction) and adapting that to the rear tank outlet. Then find a "suitable twist-on adapter for the front fitting that would allow you to twist onto the trailer sewer outlet and adapt with a rubber sewer coupler to the rear 1.5" tubing. You may find that you can leave it in place when towing, if it doesn't hang too low, or with the twist-on couplings, you can remove it to tow.

That would give you something "close to what you had on the older trailer" and eliminate the need for a flexible "Y" hose setup.

[Sherwolfe]

Originally Posted by JRTJH

I would consider buying a twist-on 90 degree elbow sewer fitting (3" connection/1.5" reduction) and adapting that to the rear tank outlet. Then find a "suitable twist-on adapter for the front fitting that would allow you to twist onto the trailer sewer outlet and adapt with a rubber sewer coupler to the rear 1.5" tubing. You may find that you can leave it in place when towing, if it doesn't hang too low, or with the twist-on couplings, you can remove it to tow.

That would give you something "close to what you had on the older trailer" and eliminate the need for a flexible "Y" hose setup.

JRTJH, Given the location of the outlet this would put this outside the frame thus putting the connection on the outside of the tires. Pretty sure I would NOT be able to leave this in place while towing. Anything I would need to remove prior to towing doesn't accomplish my overall goal. Interesting thought.

Currently with my Y connection I have placed a gate valve at the Y to prevent the black tank from pushing water back up the line to the rear gray tank. Once I did this it did make it more workable for me.