Connecting rear waste tank to front tank outlet?

[GaRoadRunner]

On rear kitchen models with two gray tanks, mine is a 27RKS,has anyone thought about connecting the rear holding tank to the front holding tank waste pipe via 4" pipe under the camper?

[rhagfo]

On our 293 Copper Canyon we have a 1-1/2” line from the rear tank to a “Y” 3” and 1-1/2”.

[travelin texans]

Originally Posted by GaRoadRunner

On rear kitchen models with two gray tanks, mine is a 27RKS,has anyone thought about connecting the rear holding tank to the front holding tank waste pipe via 4" pipe under the camper?

You're better off getting the Y connector. & a couple short hoses, less likely to get broken off during travel or it freezing/rupturing in the winter.
Plus when they plumb them at the factory there's no room to add/replace fittings & no slack anywhere, making it next to impossible to remodel without nearly tearing it all out & start again.

[JRTJH]

Our 2014 27RKS has a single sewer outlet. The rear galley gray tank is connected to the sewer outlet just behind the outlet. That "T" runs a 1.5" rigid wall plastic pile from the T to the dump valve behind the axles. The dump valve is above the coroplast so with it closed, there is no danger of freezing in the drain line.

I would not use 4" pipe, the dump valve is a 1.5" opening, so a 4" pipe would only serve as extra weight and not improve the flow rate. Besides, 1.5" PVC pipe is much easier to handle and connect than 4" PVC....

Here are a couple of photos of how Keystone plumbed my tanks. I'm really surprised that your 2017 isn't "improved" beyond my model. Seems separating the tanks would be a step backward rather than an advance in convenience.....

Anyway, it wouldn't be difficult to reconfigure and probably wouldn't cost more than $50-75 if you're somewhat handy with gluing PVC or ABS pipe together.

[CaptnJohn]

My Montana has the bath and bedroom in the rear, galley amidship near the 1/2 bath. Only 1 drain but 4 tank pulls all in the same place.

[radargil]

I used a 3" and went down the side of the frame. I posted pictures on the Everest forum but I don't know if it's still active.

[GaRoadRunner]

That's exactly what I thinking about doing. Thanks for the pictures. Don't understand Keystones thinking on this, probably saved a few dollars?

[rhagfo]

Originally Posted by radargil

I used a 3" and went down the side of the frame. I posted pictures on the Everest forum but I don't know if it's still active.

I would only have used 3” if it was a black tank, if no chunks a 1-1/2” will work fine.

[JRTJH]

Originally Posted by rhagfo

I would only have used 3” if it was a black tank, if no chunks a 1-1/2” will work fine.

Same with my trailer with the OEM tie in for the galley tank. It's a 1.5" line with a 1.5" dump valve at the galley tank. Adding a 3" line with a 1.5" valve is just adding extra weight with no gain in flow rate through the larger pipe. So unless someone were going to rebuild their galley system from the tank/valve to the new union, it wouldn't benefit them to have the extra weight and bulk that a 3" drain line adds under the trailer.