You're never too old to learn something new...

[Bill-N-Donna]

I learned that when you empty the black tank and everything stops coming out that it isn’t necessarily empty. We use a clear elbow to see when the tanks have quit draining. I have always dumped it and then dumped the grey tank last to help flush out the lines. I’ve also read postings on here about the macerators, etc… However, after watching Bingo (bncinwv) on our last outing this past weekend use the spray flushing system he has on his unit and after asking him a few questions about how it worked; I tried something a little different.

Since I don’t have a macerator or a spraying system installed on it I tried this; I propped the flush lever open on the toilet to maintain a constant flow and then I shut the drain valve on the black tank and allowed it to back fill the tank. When I opened the drain the second time you would‘ve thought the tank hadn’t been dumped at all. I did this a total of about 6 times before it cleared up and I started getting clear water from the black tank. I was simply surprised at how much debris was still inside the tank after first dumping it. I have always backed filled it and dumped it several times prior to winterization but I didn’t have any idea it would need it any other time. Many of you all may have known this already but I just thought I would pass it along for everyone’s benefit.

[Rondo]

Bill- I have the spray system on my unit and I still do it about three or four times, closing the tank valve each time and letting it fill at least 3/4 of the way before opening the valve again! I sometimes will leave the black tank valve open and close the main valve then dump the grey water tank pushing that water into the black tank some then open the main valve to clear everything. I usually dump the galley tank first then hold off on the other grey water tank to flush the lines out since it has more water in it usually! Just my way of doing things I guess1

[Waynem]

And the next time, try this:
After you think it is clear, have DW fill the bowl with water and then flush. You could also have a bucket of water to pour down the toilet. Watch the clear elbow when she does this. I have Earlene do it at least twice and have had her do it up to 5 times until I'm satisfied that it is as clear as we can get it.

[H. John Kohl]

Great learning.
If you have a master shut off valve on the black pipe where you hook up the hose. Once you have dumped your black tank close that valve and close the master. Open the gray valve and then open the the black. You will hear gurgling sounds of air moving around. when it quits both thanks have equalized. Close both gray and black tank valves. Open Master and then the black valve. you will be surprised what that back flush breaks loose.

Dave (exnavydiver) has taught me the power flush. Leave your black tank valve open. Fill your toilet up to just below the rim and then flush all that water into the black tank at once. Best to do it when it is empty. This water blast also breaks up stuff.

[8e3k0]

On our 09 3400RL the black and grey tanks will not empty completly unless you can get the nose of the monty up. After using the Monty full time for 3 months and not having a chance to do the above procedure, there was a lot of solids that had built up and literally stayed in the tank. We are on a farm, so I filled both front tanks to the full mark and then went out on a field with a hill, nose pointed up, leaning to the drivers side and dumped, wow, lots of sludge, did this procedure twice and the tanks finally cleaned up. I think that when the tanks are mounted in the factory they do not have/allow sufficent slope when unit is level. Also if your unit is leaning to the passengers side (which is typical at most dumps) the tanks will not empty completely.
Good preventative maintenance would be to fill the black water tank periodically with water a couple of times and hopefully most sludge build-up will disolve and flow out.

[garyka]

I run the rinse while dumping the black tank till the water is clear and then I dump two 5 gal pails of water down the toilet and this breaks up a lot of stuff.

[Mrs. CountryGuy]

More water, less paper, more water - - - -

We have been known (on more than one occassion) to pull up on ramps at those dump stations that are so far off level.

Power flushes are a powerful thing (sorry, could not help myself, pre-java morning). Been using them for years and years.

[ARJ]

When I am ready to dump, I fill the black tank up to the tippy top with water, dump it and then do it again. I follow by dumping the galley and then the grey tanks. Never any problems.

I do charge the black tank with about 5 gallons of water before using.

Periodically, I use a long piece of 3/4" copper pipe which I capped and drilled various holes in, connected to a hose to rinse & flush the black tank out.

One other thing I do yearly is put a gallon of vinegar in the tanks, fill them and let them sit for a few days. Cleans the sensors and hopefully cleans the tanks somewhat.

[8e3k0]

One of the challenges that come about with the black water tank is when you boondock for a length of time and try to conserve water.
That is when one really has to power flush that tank when water is available!!

[CamillaMichael]

In addition to many of the suggestions already made, we frequently will put about ten gallons of water in the black tank (valve closed) and add some of the tank cleaner/deoderizer prior to breaking camp and heading to the next site. This water and tank cleaner is mixed and agitated while driving. After getting set up at the next site, we will drain the black tank. Seems that no matter how clean we thought the tank was, we always get more "material," other than water, running out of the black tank.

[restez]

Just a little input here, we used the powdered Calgon water Softener, (1 cup) each time we used our old 2003 5th wheel. Never had any problems and will use it every time we take out our new Montana. Dealer said the tanks were very clean like they had never been used!

[richfaa]

And after you have done all of the above fill the black tank about 1/4 full before you move to your next stop then dump when you get there..lots of stuff.

[H. John Kohl]

And along with the 1/4 tank of water add calgon, laundry soap and if you really feel there is stuff on the side a bag of Ice cubs just before you pull out. The ice floating around will chip stuff away. too.

[sreigle]

A couple of years ago Darrell, manager at the Keystone Service Center, told us to use Pine Sol. He even wrote that on the service ticket. So we quit using the more expensive Calgon and have used Pine Sol ever since. Actually, we buy the Walmart store brand equivalent that costs less than a buck for 32 ounces. I put in 3 or 4 ounces after each dump.

Like most others here, I first dump the black tank, then leave the valve open while dumping the galley tank. The clear elbow shows a lot of black tank residue. Then I close the galley tank valve and open the shower tank valve, black tank still open. Still more black tank residue exits. Then I use the black tank flush. Sometimes I close the black tank valve for about 3 minutes (makes me nervous to wait too long) but more and more I just let the black tank flush run until the water is clear. Usually I set a timer for 20 minutes, then go look to make sure it's clear. I guess we each have our own way of doing these things.

[bill maietta]

A little off topic I know but how do the tanks hold up to the weight if you tow while under load. Sometimes there is no dump station and you have no choice but to move on full. I am concerned about the weight on the tank straps.

[mtpocket2]

I travel with a full fresh water tank all the time. Have not had any issues. I would hope the tanks and retaining methods are designed to take the fully loaded tanks. I have had to leave with a full tank or two due to a dump station being closed otherwise we try to dump before leaving.

[Rondo]

There have been several threads on the subject of the tanks on the Montes springing leaks, cracking or splitting! You might want to do a Search from the search engine here and check to see what you find. I, myself, do not carry the tanks full if I can help it! I do carry some water in the freshwater tank and some liquid in the others but not a whole lot. I keep enough water or liquid in the black tank so it will not dry out and possibly create some real problems in it. It also sloshes around some and cleans the tank some. If you go under the unit and pull down the belly you will normally find there is very little support under the tanks period. If I'm not mistaken Montana has started to put some strapping under the newer units but it is not enough to handle a full tank bouncing and sloshing around on the road especially if the roads are rough or the seams are washboardie! IMHO-- I would not run full tanks any further than I had to, to much damage can happento them! This again is MHO only!

[blarkman]

Everestt had a problem with dropping tanks a couple of years ago, I don't know what the outcome was just that they had insufficent strapping to hold tank in. There was quite some discussion on the Everestt site
I always dump when I leave when there is a dump station in park unless it is real cold,like 14-18. I did add a clear elbow on dump valve sure eliminate guessing how clean the black tank is.
bob

[sreigle]

We have heard of a few problems with tanks from driving with them full but the percentage is very small. We usually run down the road with the fresh water tank 2/3 full. And sometimes the waste tanks are partially full, too, depending on the situation. Our tanks were full and I dumped them this morning. We leave here Wednesday so we'll travel with a couple of days' worth in the tanks. I'm not going to dump them again that soon.

[beeje]

I am sure I will here flack for this but after I have dumped and back washed the black tank multiple times letting the tank fill with water with the valve closed ( until the water runs clear), I let it drain completely at the dump station and drive away with all tank valves open for a few miles so the remaining (mostly clean )water can work its way out of the pipes. Folks, I'm sorry but this is no different that you or some other animal pooing of peeing on your own lawn. That being said I do take into consideration where the dump station is, meaning if its remote I will do this. If its in front of the camp store etc. I will not.