Black Water Tank Shows Full When Empty

[yochanan]

I have a 72 Tradewind on which I just dumped the blackwater tank. The lights on the command center still show that the tank is full when I know that it is completely empty.

any ideas?

Thanks John

[overlander63]

It may have, umm, "build up" on the sensors making it give a faulty reading. It is, however, better than having the gauge read the opposite, that could be messy.

[scf31]

I have heard to dump a few bags of ice in the tank right before a tow,

[yochanan]

Thanks for the ideas.....It is parked. Not a tow-machine for the time being. I'll wash out the tank. Any idea where the sensors are located from the dump valve?

[scf31]

There is a thread ,rather long one at that, several months ago on this subject, it had a lot of other things to do to fix this,try a search on the subject

[tphan]

hi john- I have a '72 overlander, and the sensors on my blackwater tank were a bit to curbside from the dump valve, maybe 3-6 inches if I remember right. I reached down in there with a small wire brush and scrubbed the gook off the sensors when I had my toilet off. I suppose it is remotely possible too that someone connected the wires to the sensors wrong, so you might look at your wiring diagram and check that out. Good luck- tim

[davidz71]

John,
I had the same thing with my '86 Sovereign. In the middle of summer I flushed the black water tank, put Thetford Probe Cleaner in, filled the tank full and left it for 2 weeks. I then dumped the tank, put 2 bags of cubed ice in along with a couple gallons of water and drove around for awhile. That solved the problem. My '77 Excella 500 was starting to register a little funny so I put in a couple bags before driving 109 miles to the hunting camp. It also seemed to help as the ice sloshed around in the tank scrubbing the probes.

[Action]

On a unit that can not or will not be towed, would it be possible to manually shake the trailer from side to side and get enough slosh from ice to do the job? And get a work out too! (Assuming the insides of the trailer are secure too)

>>>>>>>>>>>>Action

[davidz71]

Originally Posted by Action

On a unit that can not or will not be towed, would it be possible to manually shake the trailer from side to side and get enough slosh from ice to do the job? And get a work out too! (Assuming the insides of the trailer are secure too)

>>>>>>>>>>>>Action

I think that a good soaking in hot weather with Probe Cleaner might do the trick but then you probably should not be using the toilet during that time.

[jcanavera]

Those old style sensors are just about impossible to keep functioning. Personally it's just not worth your time. Just watch the water level when you flush. You will know when you are getting close.

Jack

[GoldFever]

Our 92 Excella also has had the sensor reading high when empty. So when it finally goes to full then we listen until the "drop pitch" (I'm a musician, too ) reaches a D sharp on a trumpet (hahaha).

I just about wrote that this topic was good reading butt I do really need to put this sensor cleaning project back on the list....so it goes...at the bottom of the list.

Our Stream has a sensor washer built in already and so far it has not worked. Maybe I should leave the hose hooked up and run it for a long time, as in an hour or so???? I would have to attach the blue slinky, leave the gate valve open, and run it out somewhere...... (Empty first, of course)

BTW, my gate valve has been difficult to close, i.e., the wire retaining clips are extremely difficult to snap onto the little handle. Anyone know how I might fix this?????

Thanks.

OBTW (as in more Qs), how do you all get rid of the bad odiferous smells that eminate from the black tank (and maybe gray) when they are empty and you must park the trailer for long periods of time? I had to NOT use the trailer for almost 6 months and I kept pouring tank fluids into the tanks but that did not seem to help all that much (Read: stunk up the neighborhood). I eventually just filled the tank with water and then hooked up and drove to the nearest dump facility....several times...in order to be nice to those living downwind.

[jcanavera]

Just so you don't feel too bad I have owned 4 brand new travel trailers in my life. 3 of the 4 (one being an '01 Safari)used the older style sensors unlike the new ones now used by Airstream. Every black water sensor went south after the first season. The problem is you can't get those tanks absolutely clean and that's what messes up the sensor levels. So while you are putting it back on your list, understand that if by some miracle you get it working, know that it won't be for long.

The new style sensor now being used has worked well for us. We will be approaching our third season for our Classic and the sensor still works perfectly. I've never had a black water sensor work correctly for this long, but its technology is much different that the old one and doesn't have the downfalls of the old sensors.

As far a odor goes, as a practice we normally have tried to flush out the tank with at least one fill of clean water before we put the trailer away.

In some cases we cannot do that due to the hookups at some campgrounds. We always dump the tank full and if it isn't full, we make sure it is before we dump. That helps make sure you leave little behind, in case you can't do the rinse. That goes a long way in keeping the odors down.

The final thing we do, no matter what is to add a normal amount of the holding tank additive along with a gallon or so of water after we finish dumping. That leaves a little of the stuff in the holding tank that can slosh around on the trip home, and we have found it keeps little insects from reproducing down in the dark damp tank and hopefully on the trip back, anything on the walls may get washed into the liquid. As far as the chemical goes, we use one of the environmentally friendly ones.

Jack

[yochanan]

Thanks for the good info Y'all......Gary, I know that "D sharp". This will be another good opportunity to put my "perfect pitch" abilities to use.

John