Community Forums

kacol · 11-15-2011, 10:34 AM

I have a new 2011 Montana 3150RL fifth wheel, and I have been having some problems with the black tank since the first time I dumped it.

It seems to drain slower than what I have experienced with all the other rv's I have owned, in that the discharge does not have much force and the flow fills only about 1/2 of the transparent elbow going into the dump station drain.

After dumping, the monitor will show either 1/3, 2/3, or Full. It varies, but never shows empty. If it reads 2/3 full and I hold the button in for a few seconds, the 2/3 light will gradually fade out and it will stay on 1/3.

After using the tank rinse-out until the water runs clear, it still will not go to empty. However, if I fill the tank with water using the rinse-out and dump again, it drains much faster than before. It gushes out with a lot of force and fills the transparent elbow completely. The monitor will then read empty, but will go back to 1/2 or 2/3 full again after just a few toilet flushes.

Before risking an expensive repair bill (Keystone says they will not cover it unless a problem is found with the tank or monitor system), I would like to know if any other Montana owners have run into similar problems.

I do know that black tank monitors are norotious for erroneous readings, but mine was malfunctioning brand new before the tanks had a chance to scum up (ulness just one tankfull of waste will do that).

Camping World, where I purchased it, says they cannot duplicate the problem, but it happens every time I use it, but then I have not seen them take any notes when I describe the problem either.

radams · 11-15-2011, 12:22 PM

It sounds like you have a couple of different issues going on there. First of all, there is nothing very scientific about a waste tank and it's operation. There is a vent allowing air into and out of the tank and if it's plugged you can get slow drainage. One way to check that is to have someone hold the toilet in the open position while you drain and see if that doesn't change the drainage flow dramatically. If so, you need to check out the vent. If not, then something is blocking the tank outlet. Whatever is blocking the flow could move around and not always act the same. You could try rinsing, if you haven't done that already, and see if that dissolves it. If that doesn't work then you need to have a look-see with a mirror on a stick and a flashlight or one of those fiber optic cameras. There is just no way of knowing what's in there without taking a peek. Once you figure out what it is you can get out the long sleeved gloves, tongs, and bust loose a few yoga moves.

Your level detector shouldn't be acting up already so I wonder if it doesn't need to be calibrated. Check you manual and see if that isn't the case. Particularly if your gray and fresh water readings seem about right.

ajlcal · 11-15-2011, 12:27 PM

If you feel that the tank is draining too slow, then your valve may not be opening all the way or you have a blockage. I doubt that it's a blockage because your RV is new and you should know whats been going into the tank - unless you have mischievous children who dropped something down there. Try working the valve handle in and out several times to loosen it. I have a new Keystone RV also and I have to really pull on those valve handles to open them. In fact, the first time I opened the valves I though I would break them from pulling so hard.

nosticks · 11-15-2011, 03:23 PM

Since you have a Montana, you might want to join the Montana Owners Club. There are a few thousand owners over there that either have had the same problem or similar. It's free. Here is the web site Montana and Mountaineer Owners Campsite in Cyber Space

Always-RVing · 11-15-2011, 03:41 PM

There could be something partially blocking the opening that was loose inside the tank from manufacturing. If RV water off, tank emtpy and somewhat clean, you can stick a hose from the toilet down to the opening and from the opening up to the toilet.

New tanks use a outter pad technology instead of pins (resistance sensor) that penetrate the tank wall.

New Technology:
The outter stick on pads are sensitive to RF interference and tank wall buildup that can give false readings.

http://www.touchsensor.com/pdfs/1803_SensaTankRV_3.pdf

shortlance · 11-16-2011, 03:52 PM

I have heard stories of the plug from drilling the drain hole in the tank being left in some tanks. If that would be the case with yours the plastic circle could find its way to the drain hole and partially block the drain.

jackson47 · 11-19-2011, 10:56 AM

We have a '11 Montana High Country. My black tank operation is much like you are experiencing. Somewhat slow flow and the gage shows full after dumping. Repeated back flushing will sometimes show empty then next dump gage shows full or 2/3 full. I thought my black tank knife valve was leaking so an authorized Keystone service center filled the black tank check for leaks then flushed out the tank. Black tank shows 2/3 full.