1999 model holding tanks

Keep the water inside the pipes, tanks, and sinks
Post Reply
twistedskipper
Weekend Camper
Posts: 45
Joined: Fri Apr 04, 2014 10:10 am
B190 Year: 0
WBCCI: 0
Location: Longmont, Colorado

1999 model holding tanks

Post by twistedskipper »

Hi, all. New 190 owner, and new to this group. I look forward to gleaning a lot of information and, hopefully, contributing some eventually.

This will be our first season with our 1999 190, and I have yet to find any other 190's or owners with the same holding tank dump set up that we have. I've had this discussion at airforums.com, but nobody there recognizes my setup.

The late model 190's with the stand-up shower and the toilet on the driver side facing center (~1997 and later), seem to all have a smallish black-water holding tank directly beneath the toilet (above floor level), and a very large grey-water holding tank at the rear beneath the floor, where the spare tire would be on a standard E-350 van. The factory specs say the black-water tank is 9 gallons, and the grey-water tank is 27.5 gallons. Just eyeballing my tanks, I tend to agree with the specs.

Generally, it appears that late-model 190's have two dump valves: one in the outlet line from the upper black-water tank (accessible from the side of the van, just aft of the hookups panel), and one in the outlet line from the lower grey-water tank (accessible from behind the van, beneath the left side of the bumper). These valves both allow flow to the same eventual outlet for dumping. I assume in this configuration you'd hook up your sewer hose, pull the black valve to dump that tank, then close the black valve and pull the grey valve to dump that tank. Does this sound familiar to other late-model owners?

My 1999 model (March 1999), has only a single dump valve, right at the sewer hose connection point (see attached photo). There is no other valve in either the black or grey water dump lines. So, anything going into the toilet goes directly through the upper (black) tank and down into the lower (grey) tank. The grey lines from the sinks and the shower all go into the lower tank, as you'd expect.

To dump the tanks, I would just hook up the sewer hose, and pull the one valve to dump the lower tank. The upper tank should already be empty by virtue of everything flowing immediately into the lower tank.

You'd think I'd welcome the simplicity of this setup, but I have a couple of concerns.

The most vexing concern is that there is no way to hold liquid in the upper (toilet) holding tank, which means solids will have trouble flowing out on their own. In fact, there are significant solids sitting in there right now from the previous owner. It seems like I will have to aggressively rinse this upper tank with a wand before dumping, and maybe even in between dumping, if solids accumulate too much or start drying out. I can't even dump ice cubes in and drive around to break up solids, as I have seen suggested, since the ice cubes will just slurry right down the drain into the lower tank.

The other, less significant, concern is that my total holding tank capacity is effectively reduced by 9 gallons, since I can't actually hold anything in the upper (toilet) tank, other than whatever solids don't immediately drain away.

Are there any other late-model owners with this single-valve dumping setup who can confirm all of the above, and give me any advice on managing that upper (seemingly pointless) tank?

Thanks!
Attachments
Single dump valve on my 1999 B190
Single dump valve on my 1999 B190
DumpValve145K.JPG (144.06 KiB) Viewed 9926 times
--
Tim
1999 B190
User avatar
Mark
Seasoned Traveler
Posts: 177
Joined: Tue Mar 25, 2014 3:03 pm
B190 Year: 1997
WBCCI: 0
Location: I get my mail in Carson City, NV

Re: 1999 model holding tanks

Post by Mark »

Tim,

I was just looking at my 97 and can see where the black water dump pipe intersects (after its valve) with the gray water dump pipe. I'll bet yours was damaged somehow and that's how they fixed it.

Working with that type of pipe is pretty easy. I'd cut off what you have now and simply add a black water valve and intersect it with your gray water valve. You may have to remodel both valves.
Black-and-gray-dump-valve.jpg
Black-and-gray-dump-valve.jpg (137.99 KiB) Viewed 9919 times
Can you work out what we're looking at here? The black water is coming down from out of the floor to its dump valve and the gray water is coming out of its tank, passing through its dump valve and intersecting with the gray water discharge.
If it ain't fun - it ain't done!
twistedskipper
Weekend Camper
Posts: 45
Joined: Fri Apr 04, 2014 10:10 am
B190 Year: 0
WBCCI: 0
Location: Longmont, Colorado

Re: 1999 model holding tanks

Post by twistedskipper »

Ah, yes, Mark.

I hadn't thought about the likelihood of a post-factory modification to the system. It does seem more likely that the original system must have become damaged or worn and rebuilt as it is now.

Between your photo and explanation, and the factory below-floor plumbing diagram, I think I've got the picture now, and I can see how I would rebuild it to the original configuration.

Not what I was expecting to do next, but we spent a couple years on a sailboat, so surprise to-do items aren't a surprise anymore.

Thanks!
--
Tim
1999 B190
User avatar
skater
Site Admin
Posts: 2569
Joined: Thu Mar 08, 2007 1:00 am
B190 Year: 1991
WBCCI: 13270
Location: Annapolis, MD

Re: 1999 model holding tanks

Post by skater »

Yeah, that's definitely not a good setup.

The easiest thing to do might be what we do when we're camping without a sewer hookup: we have a (collapsible) dishpan that we use when we're doing dishes, then we dump that down the toilet. It helps keep capacity in the gray tank available, and it gets more liquids in the black tank.

But really it should be fixed...
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
twistedskipper
Weekend Camper
Posts: 45
Joined: Fri Apr 04, 2014 10:10 am
B190 Year: 0
WBCCI: 0
Location: Longmont, Colorado

Re: 1999 model holding tanks

Post by twistedskipper »

skater, that sounds like a good approach to keep in mind. We'll see as we go along which tank we tend to fill up first, and how often we're not hooked up. These later models have much larger grey water tanks (27.5g) than black (9g).
--
Tim
1999 B190
User avatar
skater
Site Admin
Posts: 2569
Joined: Thu Mar 08, 2007 1:00 am
B190 Year: 1991
WBCCI: 13270
Location: Annapolis, MD

Re: 1999 model holding tanks

Post by skater »

twistedskipper wrote:skater, that sounds like a good approach to keep in mind. We'll see as we go along which tank we tend to fill up first, and how often we're not hooked up. These later models have much larger grey water tanks (27.5g) than black (9g).
That's a good setup - usually people fill the gray tank much faster.
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
Post Reply