Montana 2008 3400 5th wheel leaks clean water in upstairs when running black water tank scrubber. Don't understand why water is showing up way above the black water tank. Its almost like water line is just below bedroom floor.

I had the same thing happen to 2010 3400Rl. There is a vacuum breaker/check valve located in the wall behind your shower controls that has gotten cracked or damaged. I accessed mine by removing the shower controls and reaching into the wall and pulling the pex type tubing through the opening. I did replace mine but I really don't think it's necessary since this line is NOT tied in in any way to your fresh water lines in the rest of the coach. You can get the needed fittings at your local home center to fit the tubing together if you don't want to replace the broken piece. P.M. me if you have any questions and I'll be glad to help. Tim

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I had the same problem. It was a check valve. Replaced it with a elbow where it was connected. Told it was required by law in some states. Don't know why, it is in no way connected to the fresh water system.

2-MTnesters wrote:I had the same thing happen to 2010 3400Rl. There is a vacuum breaker/check valve located in the wall behind your shower controls that has gotten cracked or damaged. I accessed mine by removing the shower controls and reaching into the wall and pulling the pex type tubing through the opening. I did replace mine but I really don't think it's necessary since this line is NOT tied in in any way to your fresh water lines in the rest of the coach. You can get the needed fittings at your local home center to fit the tubing together if you don't want to replace the broken piece. P.M. me if you have any questions and I'll be glad to help. TimBOLDFACE added.The purpose of the vacuum breaker is NOT to protect the RV water system, but to prevent a potential cross-connection with the campsite water system should supply pressure be lost. If that were to happen and there was no vacuum breaker in the line, waste water could be drawn out of the black tank and into the campsite water lines, with the attendant problems of system contamination, including possible spreading to RVs in other campsites when pressure is restored, etc. Please, for your own peace of mind and the health of other campers, make sure you have a functioning vacuum breaker on the black tank flush line.

Passin' Through wrote:The purpose of the vacuum breaker is NOT to protect the RV water system, but to prevent a potential cross-connection with the campsite water system should supply pressure be lost. .... Please, for your own peace of mind and the health of other campers, make sure you have a functioning vacuum breaker on the black tank flush line.This is correct. That vacuum breaker does fail from time to time. You do need a vacuum breaker in the line to prevent contaminating the water system. So you really should not replace it with a 90 degree elbow.

Black water tank scrubber leaks water inside trailer

mowermech
Explorer
Nov 27, 2013
elkrott wrote:
Thanks for the information will see if I can get to the valve through shower controls.

In the Monaco McKenzie I used to live in, the vacuum breaker was in the wall next to the shower. On the other side of the wall from the shower was a picture or mirror (I don't remember which). Behind that thing were the shower water lines and the vacuum breaker for the black tank flush. The leak was a loose fitting. Tightened all the fittings in there, and no more problem.
Michelle_S
Explorer III
Nov 27, 2013
I understand and agree with everyone about the Vacuum Breaker, but in most, not all, CGs they use Back Flow Preventers on the Water lines (required by County Health in many places), so as long as it's in place and functioning as designed you couldn't create a siphon action anyway.
Me_Again
Explorer III
Nov 27, 2013
The valve is there to prevent a siphon of tank contents from occurring. Ask me how a know. Install a shutoff valve if you are going to remove it. Chris
2-MTnesters
Explorer
Nov 27, 2013
WeBeFulltimers wrote:
Look inside your galley pantry for an access panel made from plastic and screwed to the wall. Remove the panel and you should find what you're looking for. No need to remove shower controls. Will probably need to have the bedroom "pocket" door closed. I used to have 2008 Montana 3400RL.

On the 2010 Montana there is no access panel in the pantry, wish there were, that's why I mentioned removing the shower controls. Great suggestion, much easier solution if there is one.
WeBeFulltimers
Explorer
Nov 27, 2013
Look inside your galley pantry for an access panel made from plastic and screwed to the wall. Remove the panel and you should find what you're looking for. No need to remove shower controls. Will probably need to have the bedroom "pocket" door closed. I used to have 2008 Montana 3400RL.
dalen
Explorer
Nov 27, 2013
I had the same problem with my 2007 Raptor,also made by Keystone. I found the check valve replacement at an rv dealer for $60 but I did not buy it. I sent an email to the folks at bandbmolders.com (they make the valve). They sent me a replacement valve for free. The only thing they ask was that I return the defective one in a self addressed stamped envelope which they supplied, so their engineering department could find out why it failed. They were very nice to work with and stood behind their product.
elkrott
Explorer
Nov 27, 2013
Thanks for the information will see if I can get to the valve through shower controls.
Paul_Clancy
Explorer
Nov 27, 2013
These valves usually fail because owners forget to winterize the black flush line. Water sits in the valve and freezes cracking the valve. Happened to me so I replaced with some shark bite fittings. None of the dealers I could find had a replacement valve.
2-MTnesters
Explorer
Nov 26, 2013
I don't disagree with what has been mentioned as far as the check valve preventing the fresh water becoming contaminated, however, in the Montana 3400RL the water line is installed in the wall of the bathroom. This means that the tubing is elevated approximately 4+ feet above the black waste tank then drops back down to the waste tank where it is installed in the top of the tank. The only way there would possibly be cross contamination would be if the tank were totally full, the hose was hooked up and there is no water pressure at the spigot and even then the waste would be backed up into the toilet since where the check valve is located is above the level of the toilet. Most people do not leave the flush hose hooked up. I do agree that there could be contamination, but not likely. Just my opinion.
texasclarks
Explorer
Nov 26, 2013
I had same issue on my TT. Quick and inexpensive fix with This