2 gray tanks 2016 passport

[rjrebeiro66]

Purchased a used 2016 passport 2770rb and have it on a permanent site. Been here for 5 days and galley sink wouldn’t drain. Discover I have 2 gray tanks. Drain rear tank into hookup. Gray #2 showed full. Open hose connection and let it drain on the ground. Gray #2 empty. My question is if I open gray #1 then open gray #2 will it flow to #1 and then into sewer outlet.

[Canonman]

Ours does not work that way. If you look underneath the trailer you should see the galley tank drain tube running to the main waste exit tube. Look for about a 1" drain pipe going into a 3" pipe. Your bathroom grey tank is also plumbed into the 3" exit. After we drain the black tank we close that valve and drain the galley tank. We close the galley valve then open the bathroom valve. No way the waste water flows from one tank to the other.
Be careful dumping even grey water to the ground. Some places have a real issue with that. We camped at a remote Forest Service CG and were trickle draining our galley water into a hole I dug for that purpose. After a pretty good scolding from the camp host, I asked how the tent campers a couple of sites down were disposing of their grey water?? I guess filling a bucket and pouring it out is OK so that's what I did. Host was a bit "pissy" about it but didn't say anything more:) I did refill the hole though.

[flybouy]

I think the no gray water draining was a remnant of the days when detergents contained phosphates. I had a "similar" discussion and asked the cg host if he washed his vehicles with a catch basin under them. After a look of puzzlement followed by the ah ha look he said have a good day and left.

[LuvsPalmTrees]

flybouy I think you are correct. The phosphates would do damage to the environment but now everything is phosphate free. Ever since we started camping I would do the dishes outside and then dump the water in the back of the campsite. Other campers would dump it on the road.

[travelin texans]

Some folks with 2 grey tanks add the twist on valve to the rv sewer hose connection & with it closed open both grey valves to equalize the 2 tanks, getting full use of both tanks. Just be sure to close both greys & open the added valve before draining the black.

[Ken / Claudia]

What you do not mention is there 2 open dump pipes into the sewer? Normally there is 1.
So, if 1 dump pipe into sewer than you have 3 tanks, 3 valves and all flow with their own valve through 1 large dump opening.
Some may be different due to past owner or design.
A permanent set up I had I left the grays open onto the always connected sewer. Black closed to build up the contains and open when near full. On that day I closed and filled a gray that was dumped after the black. Do not leave the black open, it will back up with solids, the grays will not.

[TeriADN2004]

Do all Passports have 2 black and 2 grey tanks? My control panel has buttons for 2 each. How do you switch over to the 2nd tanks?

[Hebee]

You need to get a Y fitting and use two sewer hoses. I put a cap on the sewer hose from the sink and leave it near the sewer connection. since I empty the tank 1/black water more, I hook the Black and grey 1 to the sewer connection in the ground. Every couple of days, I unhook the sewer connection and connect the sink/tank 2 hose to the hookup. I drain tank 2 and then re hook the black and grey 1. A Y fitting is good but you need a valve there so you don’t back up black water into the sink hose.

[chuckster57]

Do all Passports have 2 black and 2 grey tanks? My control panel has buttons for 2 each. How do you switch over to the 2nd tanks?

Common for RV manufacturers to use one panel for a number of different models. So to answer your question, you probably only have 1 black tank. You might even have a blank plug where a switch for a second slide would be.