3650RK Sewer Drain modification

[Icehouse]

I would like your thoughts. For those not familiar with the 3650RK, we have 2 holding tank dump points - one in front of the tires and one about 2 feet from the rear end. This obviously requires two sets of sewer hoses, walking back and forth the RV to dump, one really long dump hose for one end or the other. Question: does anyone see an issue with combining these two into 1 (one) dump location? Will the loooong run of PVC from the tank be an issue (assuming I can keep a decent slope). I would make the long run from the galley since there would be no large solids or paper from that tank.

[Waynem]

My very first thought is the fumes that may come back up through the drain in the gray water tank when the two are combined. Just don't light a match. :-) You could put a "p" trap in the gray water dump line. The 'p' trap in the sink may not be sufficient.

[bw2]

The 3400RL's galley and gray connect together. The run is not very long, so I wouldn't think there should be a problem as long as there is enough slope. I added a shut off right at the output where you connect the sewer hose. An earlier thread, someone indicated they did the same and opened the gray and galley shut offs and allowed the gray to use the underbelly pipe and the galley tank for additional holding capacity while boon-docking. I have not done that but if and whn, I will give it a try.

[GregN]

They must have changed the the layout on the 2007 model. I have the 2006 model and I only have to use one sewer hose connecting just fore of the tires. The galley tank drain line runs from the rear to this connection. The pipe is only a 2 inch pipe. The valve to dump the galley tank is in the rear near the rear jack. So far I have had no problem with fumes coming up into the galley from the tank.

[Hemlockusa]

I have a 2005 3650RK, Same set up as Greg. Just one dump, my dump valve is back to the rear for the galley, but that line runs into the regular dump line. I have had no problem with fumes or smell. Your unit is the first I have ever heard of with two dumps.
You should just run that line into the main dump. remember 1/4 slope per 10 feet.
Safe Travels John

[scductman]

My 06 3650RK also has all tanks to one outlet like john and greg. I think all drains are traped. you should not have any problems with gases I dont. I now wonder if the 2007 has changed. bobby

[Icehouse]

Well they go cheap on the '07. my dump valve is near the rear, but it does not connect to the front dump. Thanks for mentioning it is a 2" pipe - never thought to change the size. This will give me more freedom on the slope. By the way, does your galley underbelly pipe cross OVER or UNDER your axles before it connects to the other pipe?
Thanks guys
Bernie

[DONnANNIE]

I have a 2007 3650RK and it has two separated drains.(Black & Grey up front and galley in the rear)

[scductman]

Bernie my 06 drain is routed over the axel rite up under the belly. It is graded down coming to the 3" drain. but I dont think mine is 2" I think it is smaller but now I am not sure. I have been working under mine on the tanks for a month but my brain is old so I have a hard time remembering things LOL. bobby