WaterLeaks Power Rinsing/Flush Any Suggestions 2021 Tab 400

JB67

Greetings All,

My wife and I have run into a situation where when we hook up the hose to do a power flush of the black water tank that we notice a small leak of water.  We only notice this when we do the flush with the hose hooked-up outside.  The water comes out on the drivers side sitting area of the table in the eating area.  I have traced it to the bathroom area so I know that is the source.  This leak only occurs when doing the outside water hookup to flush the black water tank.  

On a side not we did hit a tree limb that was in the road and it damaged the black water handle.  Having said that we had no problems when we went to dump the black tank.  No leaking.  I am thinking that somehow when the limb hit the black water valve handle, that it must have some how damaged the inside sprayer(s) on the black tank.  Looking for any insight on why this leak occurred. It started after we hit the limb and It only happens when we hookup the outside hose to the blackwater clean out and start the power flush. The water is clear so it is not black water that is leaking to the inside of the camper

The water comes out on the drivers side of the table in the eating area.  

A couple of questions:

1). Is it possible to easily check the black water tank to see if something is going on with the water coming from the outside hose to the sprayer on the black tank?

2). Has anyone ever had to fully replace their black water tank and if so just how expensive was it roughly?

3). Does anyone have any suggestions on how to proceed?

Thanks and feedback is much appreciated.

Horigan

Other folks have posted here about a leak at the connection between the hose attachment outside and the tank.  You can access the backside of that connector by removing the outside shower box.  Check interior hose connection on the inside of the flush port.  While you have the shower box off, you can replace the stiff white shower hose with a more flexible metal covered hose, similar to what's used on the inside shower.

Jake_Elwood_and_us

I just fixed this leak on my 2021 400 and the loose connection was inside at the back of the P3 Nautilus system. Check that fitting while running water to the black tank, that was what I did and it was leaking.

Binghi

Jake_Elwood_and_us said:

I just fixed this leak on my 2021 400 and the loose connection was inside at the back of the P3 Nautilus system. Check that fitting while running water to the black tank, that was what I did and it was leaking.

Exactly. This is a known issue with the 2021 400 BD. Same thing happened to me. The leaked water from the loose black water connection in the Nautilus compartment spreads over the trailer floor and can pop out anywhere. Have to tighten that connection, or better yet have the dealer do it if it is still under warranty.

manyman297

I know the black tank check valve is behind the bathroom sink area (when using the tank flush you can hear it in the bathroom). If you see water under the driver side dinette seat then that feasibly could be coming from that area. I doubt your black tank connection behind by nautilus would leak all the way up to that area. 

qhumberd

These pics are from behind the folding sink in bath. Not too hard to remove but still a pain. Two white hoses here rise up to check valve and return to black tank.

If you have to check the black tank flush valve this is how it is plumbed in the 2019. 400. It goes to an outside driver side hose connection and you can get to that by removing the outside shower box. In the Nautilus system the outside connection is ? at the Nautilus panel and from there it must run to bath but have not seen any pics of that in 2021 400.

The valve is just hand tight hose fittings in mine so maybe could leak there. Or valve could crack and leak if it retained water, which is why I blow these hoses out now during winterizing.

Gherzig

This is helpful information.  @qhumberd just to be clear, are you saying that you blow pressurized air into the black tank flush intake connection in addition to the fresh water intake?

[Deleted User]

This continued to be an issue on the 2022 400 as well. My friend had to take hers in twice for exact same issue. Happened first time they used it. 

Also make sure you use pressure regulator on black flush hose too. I didn't and also had a leak.

Jake_Elwood_and_us

TabbyShack said:

This continued to be an issue on the 2022 400 as well. My friend had to take hers in twice for exact same issue. Happened first time they used it. 

Also make sure you use pressure regulator on black flush hose too. I didn't and also had a leak.

I'm not sure one would need a pressure regulator on an open fill meaning no pressure buildup as it empties into  the black tank. If one did use a pressure regulator it seems prudent to have a second one same as a second hose to protect from contamination.

[Deleted User]

I thought that too but I was wrong. I didn't use pressure regulator on my 2022 400 and my water alarm went off and i had about a cup of water to get up. I have two hoses and two regulators. One is dedicated black and one dedicated fresh.  

It wasn't leaking on the backside of the Nautilus though.  It was one or more elbows along that line.  

JB67

Jake_Elwood_and_us said:

I just fixed this leak on my 2021 400 and the loose connection was inside at the back of the P3 Nautilus system. Check that fitting while running water to the black tank, that was what I did and it was leaking.

Thanks Jake.  I will check it out.

JB67

qhumberd said:

These pics are from behind the folding sink in bath. Not too hard to remove but still a pain. Two white hoses here rise up to check valve and return to black tank.

If you have to check the black tank flush valve this is how it is plumbed in the 2019. 400. It goes to an outside driver side hose connection and you can get to that by removing the outside shower box. In the Nautilus system the outside connection is ? at the Nautilus panel and from there it must run to bath but have not seen any pics of that in 2021 400.

The valve is just hand tight hose fittings in mine so maybe could leak there. Or valve could crack and leak if it retained water, which is why I blow these hoses out now during winterizing.

Very helpful. Thanks.

qhumberd

Gherzig said:

This is helpful information.  @qhumberd just to be clear, are you saying that you blow pressurized air into the black tank flush intake connection in addition to the fresh water intake?

Yes I did use a low pressure air blowout on the black tank flush connection when I last winterized. The hoses are vertical and should drain but the connector at the trailer has a ? Backflow valve and I am not sure if water could get trapped there or in the one way flush valve and damage it upon freezing. Maybe not a concern but when I saw how covered the valve is I decided it was worth a few extra moments when I was blowing out lines.

manyman297

I’ve started using a pressure regulator on my black tank flush just out of caution. 

Binghi

Use a pressure regulator

[Deleted User]

I'm saying that mine for sure leaked inside on the floor without the regulator.  A regulator is needed on the black flush. 

Denny16

The Black Tank Flush is a pressure nozzle, and this creates some back pressure, so a pressure regulator on a city water connection greater than 50psi is an excellent precaution, and one that I take.  I also have a portable pressure gauge to check a water connection pressure.  

 Many city water hookups are in the 60-70psi range, which might cause a leak on a pressure fitting.  This is why home plumbing is all glued connections on PVC pipes, no pressure fittings on pipes that are not reading accessible.  Most pressure fittings are on the faucet connections, where they are easy to check and tighten as necessary.  

An RV going down the road is like a house in an earthquake, everything can get shaken loose, if not properly secured!  I always error on the side a caution.
 Cheers