View Full Version : 2010 NCV3 Factory Roof Air Conditioner Leaks

08-20-2013, 11:55 AM
The purpose of this thread is to share my experiences so that others may avoid the same fate. In June 2011 my wife purchased a 2010 MB Sprinter (passenger version, as a demo with 2k miles) from our local MB Sprinter dealer, Mercedes of Midlothian. This purchase was a Father's Day present to me with the intent that we would convert it and enjoy it over the years with our growing family. However, I cannot report that experience has been pleasant. In short, I would advise all those considering a Sprinter purchase to avoid the factory roof air conditioner!

Our dealer has attempted to repair the leak on three occasions. Each time he assures me it is fixed. However, it never has been.

I will post more later, but for the moment please take a look at these videos to see what might happen to you if you select the factory roof AC.


08-21-2013, 01:44 AM
I had a problem just like this a few weeks ago.

The van had been into a SoCal MB dealership to fix the problem but it still existed.
First we discovered that the pod was loose on the roof! You could lift it up by hand a s cosh!

It is in fact held in place by a lower roof side plastic panel and has fixing screw nutserts on the weather-side of the pod carcass. The two halves seal out the weather by a thin strip rubber seal. In our case the strip had distorted in by the effects of wind flow against the loose upper pod. To make matters worse, the the last guy(s) that got at it, crossed the threads in the nutserts, tore some out, and many had been packed out with washers to get a clamping load on the upper pod & seal.
Not Good!:thumbdown:

We got a new seal MB (one side adhesive) which frankly was no better than a drought excluder strip you get at a big box hardware store! After this repair exercise I won't criticize a Landrover/Webasto sun roof seal ever again!:hmmm:

The system needs to be evacuated to remove it from the aperture and do a "propah" job of re-sealing it. I can't say that I was happy with the final re-seal but it was fixed down firmly on the roof panel when we finished. The motto to the owner "go try it"!

Now turning to the underside there are two drain hoses that we found adrift; the fixing stubs are not a good fit and we used some hose clamps to get them firmly fixed. Again the Landrover/Webasto undertray is far better at condensate/water ingress capture than the molded plastic undertray on this MB contraption!.
This area I was far from happy with!

The evap' core sits immediately above the vent grill and has an absorption pad between them.
This causes the pad to soak up the condensate on a hot damp day like a sponge then start dripping once saturated. Then its raining like your video.:idunno:

I thought this needed some more attention and design mods to make it vent/drain condensate better, but shop time got the better of us and it had to go on its merry way!

I did a follow up call last week: so far no problems but its early days yet!
A good mid Western dust wind storm at 70MPH might just jar it loose again!:thinking:

So jury is out on that little job!

07-01-2014, 07:30 PM

There is a Mercedes technical service bulletin out now for the fix you describe. This was performed on my van this spring after the five roof leak repairs (4 gasket related, 1 for condensation within the rear roof unit). This seems to have stopped the problems for the moment.

Came across this report while researching my roof leak problem, the reporter must have downloaded the video of our van and incorporated it into their report (that's it with the red cabinets and sink)... http://www.nbcmiami.com/video/#!/on-air/as-seen-on/Mercedes-Hit-by-Lawsuit-Over-Sprinter-Model/255437581

It appears MB has a class action suit against it in California for the rear AC roof leak problem.

07-03-2014, 01:31 PM
I've to suffered the "interior waterfall" problem on two occasions now, the first time I brought it to the dealer they mentioned the condensation problem, but sure enough 2 weeks latter it was raining inside my van again, this time they are dismantling the top part of the AC and applying some sort of waterproofing gunk, is this what the latest MB report suggests?

11-02-2014, 07:25 AM


11-04-2014, 02:35 PM
Great videos, I especially like the second with the kids screaming.

BTW, shortly after our third repair I wrote a letter to Steve Cannon, CEO of MB USA, regarding our roof leak. The company assigned another representative to assist and offered an extended 3 year warranty (taking our 2010 Sprinter out to June 2016). They also sent their corporate technical guy down to inspect the final gasket repair. He was helpful and informative. Key quote of his, "These roof leaks are a known problem and sometimes you have to go beyond what the technical service bulletin states in order to fix them." When I asked why a known problem had not been offically recalled he declined to comment.

We stood in my black van for an hour on a sweltering summer day while another mechanic stood on a ladder and hosed down the roof. No leaks so I drove away. Six months later I was back for the condensation problem (which appears to be fixed now that they drilled some additional holes in the roof AC per the newer technical service bulletin).

Only problem now is that roof AC ducts have been removed and replaced so many times they are floppy and don't fit well. On a cross country trip they began to droop and fall off in pieces.

11-04-2014, 10:30 PM
I remember seeing your video a year ago and thinking, well....surely there is a fix implemented on the 2013 model. So I didn't worry.

Recalls must be hellaciously expensive for Mercedes to keep shoving this under the rug and putting the onus on individual owners.

11-23-2014, 06:07 PM
Just bought an 07 passenger van with roof AC. MB dealer says leak repair will cost $1000 since they have to replace the frame and seal. I asked if they would apply additional sealant and they said No, not part of repair process.

Is there anything else I can ask the dealer to do that will help?

Anyone had any luck removing the unit altogether, since I really don't even need it.


11-30-2014, 05:11 PM
Take off the foam tape seal that is used at the factory to seal unit.
Now use some butyl rubber sealant (comes in a caulk tube) and reseal with it.
I did mine this summer and not a drop of leakage since.
Original foam seal is a complete joke.

12-01-2014, 09:06 PM
The foam seal has been changed to a wider, closer cellulose type seal, The new seal is probably going to be the fix for this. There is a new repair document for all of the ailments of these roof units. What also must be said here is that the unit cover seal and bolt holes sometimes need replacement and sealer applied to the screw heads to stop the leak.


12-01-2014, 11:28 PM
Big Blue Bus has a great write up on how to fix the leak.
If you follow the instructions you will not have a leak.
Just make sure you are careful about applying sealant to
every bit of perimeter cutout in roof. It took me about 2
hours to fix the leak. Mine only leaked once but I wanted
to fix it soon so as not to stain ceiling. Like I said, when you
see what they used to seal unit from factory it is hard to believe
it would ever work. No need to over think this, just reseal unit to roof.
(Not with foam tape)

06-26-2015, 05:09 PM
Update, my roof is leaking again. There is a puddle on the floor below the roof AC the day after a heavy rain.

When I called my local dealer to make a service appointment the manager told me there is a new technical service bulletin (i.e., method for fixing) as of a three months ago and "that should do the trick." I reminded him that is what he has told every time I've experienced this problem since purchase in 2011.

Then he told me that it feels like they've had problems with every unit they've sold with a roof AC.

My extended warranty ends June 2016. I will make the fix myself after that if needed.

06-26-2015, 05:31 PM
Yikes, we skipped the roof air because of this issue.