Black Water Tank - Montana Owners Club

randye · 06-06-2007, 09:34 AM

For General Members I've had a slight problem, my black waste tank shows 1/3 full all the time, the first week when I emptied it showed empty. Since them its been 1/3. Last night I emptied it and it showed 2/3. I ran the flush unit for about 15mins. Then it showed 1/3, no more than 2hrs later it showned 2/3 again. The dealer parts man said to put a small bag of rock salt in and small bottle of pine sol, just before traveling,that the sensor has something stuck on it. Does this sound right to all of you? Thanks for your imput. Randye

richfaa · 06-06-2007, 10:33 AM

There is a chance that something is "stuck" on your sensor..try a enzyme based treatment or ice cubes or running down the road with 1/3 of a tank of water in the tank..There is a better chance that the sensor has failed or is failing.From what we gather on the forum that is a common problem.

Cyrus · 06-06-2007, 11:01 AM

I had the same problem after getting home this week. I run extra water in with each flush but after a few trips, 2-3 days even if connected to sewer I still have the same problem.

I don't have a built in cleaning system so I use the cleaning wand down the toilet for about 5 minutes with the dump closed. Then I open it and that usually fixes the problem and did this week. I have never done anything else to clean it. It has worked every time.

Glenn and Lorraine · 06-06-2007, 11:14 AM

It is a very common problem with most all RVs and NO the sensor is not failing. The waste accumulates on the sensors causing an erroneous reading at the panel. Trying to clear the sensors is a never ending problem. Yes you can dump ice cubes in the tank and drive down the road and with any kind of luck the panel indicators will work BUT in very short order the problem will return. You can try an a enzyme based treatment. You can also use Calgon in the tanks. There are innumerable solutions to the problem of which all have a cost factor but in the end few work for any period of time. In most cases the sensors will be fouled after just a couple usages. Sure you can put some sort of additive in after each and every dump but this becomes a pain in the butt not to mention it also becomes costly. For the past 3 years I have not put any additives in my tanks. After every 2nd or 3rd black tank dump I do a thorough flushing. I have a clear elbow on the sewer hose and flush until nothing but clear water comes thru.
In my old Monty I learned thru usage when the tanks were full. The Black tank had a different sound when flushing letting you know it's time to dump.
In our new Monty we only used the sensors one time and that was while doing the PDI. We have not used them again since than. With the new porcelain toilets it is quite obvious when the tank needs dumping. The toilet will actually blow a bubble when flushing. That's gotta be the best sensor I have yet to see. Just don't be sitting when you flush.
My advise would be to forget those DA%& sensors and through usage you will learn when it's time to flush.

randye · 06-06-2007, 05:55 PM

Excellent answers from you that have been living full time, we thought as much, but the monties are quite the investment and we wanted to be sure we wouldn't screw something up. Thanks for all the help. My wife got a good laugh about not sitting when you flush, in case the tank is full and it burps, she will never flush while sitting there again.(ha ha). many thanks again Randye

crandallbradley · 06-08-2007, 04:32 AM

I don't know about the rock salt but I think that bottle would give you more problems then you had before.

padredw · 06-08-2007, 05:02 AM

This just to second the observations by Glenn above. We have had three fifth-wheels--the second and third bought new. We learned quickly that the sensors never work correctly after the first few trips.

There seems to be one exception: the fresh water gage does seem to work dependably, and did in all three of our fifth-wheels (each by a different manufacturer). I use it to fill to the desired level and then it gives me a pretty good idea of how much fresh water remains.

The other sensor indicators: black tank, galley tank, and gray water tank should be forgotten. There are clear indications (learned by observation and experience) when those tanks are getting full, but that does not include the sensor indicator lights.

Cyrus · 06-08-2007, 06:56 AM

I have been wondering if it best to leave the black tank dump valve off even when you have full hookup at campgrounds and just dump before you leave or is it best to leave it open. Didn’t know if only dumping when full helped clean it out better and keep the indicators working longer?

Mrs. CountryGuy · 06-08-2007, 08:18 AM

Leave the black tank valve pulled (in the position you use to drain the tank) and you will end up with Mount Cra**** in that tank. You must have fluids.

More water, less paper. We live by that rule.

Dump when necessary when on full hookup sites.

By the way, many leave gray and galley open, we don't do that either, as there is a lot of "crud" floating in those tanks too. If they drain continuously, you will eventually have dried concrete like stuff in the bottom of those tanks.

Many who have washer/dryer do leave tank open, IF it dumps to the gray. Might do that if we ever have a W/D. Some models for a short period of time were plumbed so that the W/D dumped into the black tank, you have my sympathy if that was one of you. (that was NOT one of Keystone's brighter decisions, thankfully, they reversed quickly)

Keep the valves in the closed position, ignore the silly gages, if you feel need to clean, suggest the water softener stuff, would not waste good bag of ice (have much better uses for ice, thank you).

Have never heard of putting rock salt down there. sure would not melt tho, would it??

richfaa · 06-08-2007, 09:16 AM

The only gauge that does not work properly on our 3400 is the galley tank guage..all the others work perfectly. The tanks Do require proper usage and maint.We have had 4 other campers with guages and all of them worked as long as we had them. I sort of figure that they are there, we paid for them, they should work..If they never work properly and never have and we should pay no attention to them..then why are they there and why do we pay for them???Right now I suspect the micro switch in the panel indicator is bad for the galley tank. The only way I can prove that is to replace it with another from a 3400 Montana which I will do as soon as I come across another 3400...or wait till the rally and get one from the factory.....

Mrs. CountryGuy · 06-08-2007, 09:46 AM

Rich:

you ask: If they never work properly and never have and we should pay no attention to them..then why are they there and why do we pay for them???

well,

Why are they there?? So we have something to discuss, minding that we must discuss with some discretion. Hard to do when you are talking sewer stuff, eh??

Why do we pay for them?? I have no idea, if I could opt out, I WOULD!!!!!!!!!!!! Waste of my time and my $$.

ols1932 · 06-08-2007, 11:20 AM

We don't use our sensors since they don't work (except for the fresh water sensor). No matter what we have done to try and keep them clean, using all the suggestions: enzymatic chemicals, ice, pine sol, calgon, rock salt, etc., nothing has worked. For almost seven years in this rig and over 30 years of total RVing, we've never had sensors that worked. I know Rich says his work and I've done everything he has done, to no avail.

Experientally, we know when to dump!

Orv

sreigle · 06-08-2007, 01:44 PM

Freshwater is the only one that works reliably on our Montana or any of our five fifthwheels (over the years). And even that is not really accurate. The 1/3 reading must be way below the 1/3 point on the tank.

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