2007 Interstate black/grey tank leak

[myrondad]

My '07 Interstate/Sleeper forward has dual leak in the top of the black/grey tank. The ABS pipe for the the sink is completely unsealed at the tank. Is the sink pipe supposed to be fitted into a flange? The shower drain is sealed but seems to be leaking at the tank entry point. The toilet seal seems to be okay? I have not dropped the tank so most of my diagnosis is by feel. Can anyone tell me how these drain pipes are supposed to be configured with or without flanges? If the sink and shower are simply sealed what sealant should be used?
I'm 3 years in the Interstate but new to the forum.

[InterBlog]

Originally Posted by myrondad

My '07 Interstate/Sleeper forward has dual leak in the top of the black/grey tank. The ABS pipe for the the sink is completely unsealed at the tank. ... Can anyone tell me how these drain pipes are supposed to be configured with or without flanges? If the sink and shower are simply sealed what sealant should be used?
...

My reply here is back-filling and cross-posting information into this original question, which is a few years old now (curiously, this user seems to have gotten no responses in what is an otherwise active and verbose forum).

There is an extensive discussion thread on this problem; however, that is located on Sprinter Forum. It appears to be exclusively an Airstream problem, so the repository of knowledge should be on Air Forums for maximum searchability, I think.

Anyway, here are our three posts describing the problem in detail with pictures, and describing our devised solution to the problem, which appears to affect many, *many* 2007 Airstream Interstates (and possibly other model years - we don't know).

THE INTERSTATE BLOG: INTERSTATE LEAKING GRAY WATER, PART 1: THE PROBLEM
THE INTERSTATE BLOG: INTERSTATE LEAKING GRAY WATER, PART 2: TANK REMOVAL
THE INTERSTATE BLOG: INTERSTATE LEAKING GRAY WATER, PART 3: TANK RE-INSTALL

Thanks again to everyone who contributes to these forums. We'd be lost without you.

Alison and Lawrence
League City TX
THE INTERSTATE BLOG

[xrvr]

In 2010 there were few Interstate owners on the forum as compared to today.

[InterBlog]

Originally Posted by zigzagguzzi

In 2010 there were few Interstate owners on the forum as compared to today.

Ah, that would explain a great deal, including why AI topics are spread among multiple forums (it has frustrated me at times because I will search one and then forget to cross-check against the others, and Google won't always pick up the slack).

[InterBlog]

Originally Posted by myrondad

My '07 Interstate/Sleeper forward has dual leak in the top of the black/grey tank. The ABS pipe for the the sink is completely unsealed at the tank. Is the sink pipe supposed to be fitted into a flange? ... If the sink and shower are simply sealed what sealant should be used?
... .

As a follow-up to this, your questions about sealant and flanges made me wonder retrospectively to my first reply whether you might have been working with an already-altered system, similar to what this other 2007 owner is facing:

THE INTERSTATE BLOG: INTERSTATE LEAKING GRAY WATER: POSTSCRIPT

This thread originated a few years ago, so if you still own your AI and eventually revert to reading this thread, we'd love to know how you resolved your issue. Thanks.

[InterBlog]

This is a placeholder comment to remind me to come back and amend this thread once we get the repair(s) done -

It turns out that it wasn't just our gray water tank that had its connections sheared off because the tank was improperly installed - our separate black water tank was affected in the same way and we just hadn't discovered it yet.

While fishing wire for a new and more sophisticated battery monitor than what came with our 2007 Interstate, we found that the vent had separated from the top of the black tank. The dark, flat foreground object in this photo is the top of the black water tank. At photo right, I've shoved a pair of tongs underneath the red and white lines to lift them up, but the shadow is casting over the area where the vertical pipe joins with the tank, so it's not clearly visible. However, the leaking is visible. The blue color is the water staining on top of the tank and running down its aft side is by virtue of the remarkable overabundance of toilet treatment that we found had been tossed into this tank prior to the vehicle's sale to us.

Everything to the adjacent left of this blue water stain is our electrical system - the converter and all the rest. It's right up against the aft side of this tank.

I wonder if perhaps I might one day find myself giving witness testimony in a liability case because some poor Interstate owner ends up getting injured by the likes of this nonsense. It's one thing to build a defective tank that is slung relatively harmlessly beneath the vehicle, as the gray tank is. It's quite another thing to do the same thing with a tank that sits nearly on top of the electrical system. Water and electricity don't mix. What Airstream has done here has gone from the unfathomably stupid to the profoundly unconscionable.

My fingers are crossed that you guys with younger Interstates have slightly better construction behind your walls. Meanwhile, we have yet another tank to re-engineer.

[avanti]

Sadly, this is typical of the kind of stuff that we repeatedly discovered over the years of ownership of our 2005 Interstate. For example, every time we filled the freshwater tank, we ended up with water on the floor inside the van. Eventually, we discovered that the clamp holding the fresh tank vent tube to its vent was never tightened. So, water splashed out of the tank, thoroughly soaked the insulation all along the wall, and eventually seeped into the van. Just one of many examples. There is no excuse.

[Protagonist]

Newer models ARE better in that regard. Plumbing in the middle of the van (except the water heater) and electrical in the back. The only plumbing-related problem I've had to date on my 2012 model was a failure of the water pump to self-prime after about a year of ownership. Vibration (apparently due to bad Louisiana roads) caused the inlet tubing to slightly come loose from the pump, allowing it to suck air instead of sucking water like it's supposed to. Easy fix to put it back the way it's supposed to be.

[Lily&Me]

Nearly 8 years of ownership of a 2006, we have not had tank problems, but did have an issue with a pipe in the toilet connection not being cut quite long enough, causing a leak that took 3 trips back to the dealership (now defunct) to correct.

The last comment from the service guy, when he finally replaced the pipe, was that he knew it was cut too short but thought he could rig something that would work.

The service tech issue aside, this was another of the quality control issues which could have and should have been avoided.

I am reading on other threads that JC is paying more attention to these things, which is encouraging.


Maggie

[avanti]

Originally Posted by Lily&Me

I am reading on other threads that JC is paying more attention to these things, which is encouraging.

I really hope so. I LOVED the idea of being an Airstream owner and would really be delighted to be enticed back into the fold someday. Squandering the goodwill associated with such an iconic brand on easily-avoided nonsense is just sad.

Glad to hear that things are looking up.

[Boxster1971]

You could download the parts book from Airstream and it might help.

Manuals, Airstream Travel Trailers, Touring Coaches | Airstream

Page IV-8 in the 2007 Interstate Parts Book shows the drain system for rear bath.
Page IV-9 shows the drain system for mid bath.

[InterBlog]

Originally Posted by Boxster1971

You could download the parts book from Airstream and it might help.

Manuals, Airstream Travel Trailers, Touring Coaches | Airstream

Page IV-8 in the 2007 Interstate Parts Book shows the drain system for rear bath.
Page IV-9 shows the drain system for mid bath.

Believe me, we are long past that stage. We got all that stuff about two months ago when we re-engineered the gray water tank. But thanks.

[InterBlog]

Originally Posted by InterBlog

Believe me, we are long past that stage. We got all that stuff about two months ago when we re-engineered the gray water tank. But thanks.

In fact, we've attempted to improve upon that manual, which is only of limited use and accuracy.

[InterBlog]

Originally Posted by InterBlog

This is a placeholder comment to remind me to come back and amend this thread once we get the repair(s) done -
.......

Here is the corresponding repair post for this portion of the plumbing problem.

THE INTERSTATE BLOG: FIXING THE BLACK / GRAY VENT LINE ON AN AIRSTREAM INTERSTATE

[knotdonne]

I think this might be the problem on my 2007 Interstate only I don't think there's any problem with the gray tank. I wish! 'Cause it's the black tank. My husband lifted the toilet and resealed it and we crossed our fingers. Didn't work. A trickle comes out from under the cabinetry on to the floor.

I took it to the Airstream dealership in Greensburg, Pa and they were no help at all. They seemed totally unfamiliar with the Interstate. I also called the company and they didn't help either. We aren't handy. Anyone know a great RV repair in western PA or eastern Ohio?

[Chatooga11]

I had the identical problem with my Interstate. Eventually the whole plumbing system was replaced because of improper installation. Of course this was after the warrantee was up. The saddest part was Camping World had the MH for an entire summer. No camping trips.

[Protagonist]

Originally Posted by knotdonne

I took it to the Airstream dealership in Greensburg, Pa and they were no help at all. They seemed totally unfamiliar with the Interstate. I also called the company and they didn't help either. We aren't handy. Anyone know a great RV repair in western PA or eastern Ohio?

Jackson Center may not be eastern Ohio, but since they built the danged thing, they should be the experts. So if you're willing to travel a bit farther, that might be your best source of repairs.

[LB_3]

If you can remove the toilet you can repair the vent line on the top of the black tank (see comment #6). I think it only took 2 hours and repair costs were about $15. Now if you have an issue with the grey water tank, take it somewhere because that's a much more difficult repair.

I used a drimmel with a tile cutting bit to cut out the old vent fitting on the top of the black tank. I replaced it with a flexible rubber grommet which should be a bit more accommodating to road vibrations. I also replaced the existing Y fitting with a flex Y as well. Interblog has this documented on her blog. Note that due to the close proximity to the grey tank vent line, I needed to use a 'street tee' fitting to connect to the flex Y fitting.

[knotdonne]

Ed thanks you for this vote of confidence! He says that he couldn't see much when he took the toilet off. I gave him the manual that Interblog put in an earlier link to see the parts order and he thinks he can do it! He doesn't have a drimmel, but he knows what it is!
The flexible adjustments also make sense because it's fine until the vehicle moves.
Many thanks to everyone for help. Feel free to keep it coming!

[InterBlog]

Originally Posted by knotdonne

Ed thanks you for this vote of confidence! He says that he couldn't see much when he took the toilet off. I gave him the manual that Interblog put in an earlier link to see the parts order and he thinks he can do it! He doesn't have a drimmel, but he knows what it is!
The flexible adjustments also make sense because it's fine until the vehicle moves.
Many thanks to everyone for help. Feel free to keep it coming!

Glad we could help. I was initially intimidated by the thought of working on our Interstate, but with the right information and having the repair procedures broken down into steps, it's often more do-able than it first appears. In the beginning, I had planned to have an RV shop do some of our work, but the good one in our area has wait times ranging from weeks to months depending on the job. Didn't someone in the thread above say that their motorhome was in the shop for an entire summer because of these plumbing issues? Unacceptable!! I can be a fast learner when I have to be.