Vito. Mysterious Puddle at rear tailgate.

[zenman63]

Defiantly the brake light, I have had the same thing on my last Vito after MB fitted a new tailgate I had water coming in.
They did think it was a window leak but soon found the seal around the light had gone.
Look for water in the light, or steamed up inside.

 

[corned]

Hmm. The side panel water trace is quite interesting.

Does it have side windows? Or is there anything else above that with holes in it (roof for roof bars, bracketry on the van side, etc)?

Going back to the tailgate, you may well be able to pry off that light grey window surround trim; indeed you should do this, in order to see precisely where the water is entering. The brake light is looking a bit sheepish at the moment, for sure.

Good luck with it mate!

 

[ringway]

Hmm. The side panel water trace is quite interesting.

I'm not too concerned about the side panel. It has never leaked before and that was a real soking it took, I can tell you.

Does it have side windows? Or is there anything else above that with holes in it (roof for roof bars, bracketry on the van side, etc)?

It does have roof bars which were fitted after I bought the van by Hanstons (I figured if I dropped one on the bodywork while fitting it would be expensive to repair), but the fixing bolts were sealed, so I doubt they would be an immediate suspect, although you never know..

Going back to the tailgate, you may well be able to pry off that light grey window surround trim; indeed you should do this, in order to see precisely where the water is entering. The brake light is looking a bit sheepish at the moment, for sure.

Yes the trim does prise off and snap back on quite easily, so yes, it's a good idea to remove it when I next test for the source of the leak.


Good luck with it mate!

I'll test again at the weekend.

 

[Dieselman]

Defiantly the brake light,

Has it already been told to stop?

 

[BTB 500]

It does have roof bars which were fitted after I bought the van by Hanstons (I figured if I dropped one on the bodywork while fitting it would be expensive to repair), but the fixing bolts were sealed, so I doubt they would be an immediate suspect, although you never know..

The bars (or rails?) should simply bolt into the fixing points that all Vitos have built into the roof. I'm 99.9% sure these are 'blind' threaded holes ... i.e. they dont go right through. By default they are just filled with a black nylon flat-headed screw/bolt. I'm pretty sure those don't use any kind of sealant (or even washers).

 

[ringway]

The bars (or rails?) should simply bolt into the fixing points that all Vitos have built into the roof. I'm 99.9% sure these are 'blind' threaded holes ... i.e. they dont go right through. By default they are just filled with a black nylon flat-headed screw/bolt. I'm pretty sure those don't use any kind of sealant (or even washers).

Ah! When I left the van with the bodyshop they said they'd seal the threads but I'll bet they hadn't fitted the roof bars before.

That rules out the roof bars as a suspect for all future leaking Merecedes vehichles, then.

 

[malcolmsmill]

I don't know if you got it fixed so I'll chuck my two pen'th in.

I have a similar problem in the cab area of my 638 and the tailgate of a friends 639.

BOTH were due to the roof rails having moved allowing the water to get past the mounting bolts/nuts.

the movement is minute and can't be seen but it was only found after all trims and headlinings were removed.

I cured both by removing the rails and degreasing with DeSolvit degreaser and filling the area between the rubber gaskets and around the bolts with sika motorhome sealant.

whole job cost a tenner, a days hard work (without a garage you daren't leave the rails off overnight) and weeks, no.. months of frustration trying to find it.

 

[Heathen]

Ringway, did you ever get to the root cause of the leak? I have a 2010 115 Dualiner which within the last 7 days has developed exactly the same problem as you described and identical to your photos. The vehicle does not have roof rails fitted.

Appreciate your thoughts, Heathen.

 

[ibrahimx2001]

Could it not be the rubber seal that goes around the tail gate

 

[Heathen]

I do not think it is. The water ingress is coming in around the top midpoint of the grey clip on cover that fits the top half of the rear screen. This was removed recently when a sparkie sorted a fault with the heated rear screen. Should there be a seal around it?

As a temporary measure I have sealed top of it with duck tape to the tailgate.

Awaiting the next deluge!

 

[ringway]

Ringway, did you ever get to the root cause of the leak?

No, I'm afraid I never got to fix this - not long after posting, I ended up out of action for quite a while and have never had in inclination to explore further.
I can say though, that if the tailgate is left open it really does fill inside with water if there's a shower. I stop the door 18" before the closing point the let the water run out.

 

[zenman63]

I have this on the viano, not from the top like yours paul but puddles around the latch at the bottom.
I think it comes out the latch inside the tailgate.
I have done the brake light and it still leaks.
Next is look at the number plate light surround.

 

[BIG UN]

I had a slight leak on mine that started after I fitted my roof rails that looked very similar to Ringways as the water was tracking down to the back of the van, I ended up stripping everything back out and putting a thin smear of clear silicone on the bottom of the rails before re-tightening them. Job done & not so much as a spot of water!

 

[ringway]

Next is look at the number plate light surround.

Number plate surround may well be the answer in your case, (and possibly others) Zenman.

I have an idea that an ill-fitting chrome handle above the plate may be the cause of my corrosion and leaking problems.
I waited for around 6 months for the unsuccessful corrosion warranty claim before I installed the reversing camera (house in one of the number plate lights in the chrome trim) and the corrosion started from behind the trim.


Here.

I think the pictures above were taken around 15-16 months ago.






The picture below was taken around 6-8 months ago, and predictably, the corrosion has worsened since then.

The trouble with today's MB's (and other marque's) is that the paint is so very thin and offers little protection. This is often the reason for mis-matching after a body repair - The repairer puts on a coat of paint that is too thick for today's bean-counting manufacturers.



Hanston's (MB Approved) Bodyshop in Altrincham told me that when the tailgate repairs are carried out, a thin film (perhaps 0.5 - 1mm thickness) is placed between the chrome trim above the number plate handle to stop chafing of too cushion the hard trim surface against the paint finish, thus lessening the risk of damage. After reading through this thread again, another reason for the thin film application, may well be to stop water ingress?


That tailgate corrosion certainly spoils what is otherwise a super example of a much-cossetted Vito.

 

[BTB 500]

I can say though, that if the tailgate is left open it really does fill inside with water if there's a shower.

Ours has never done this - and the tailgate is left open frequently when it's raining! The water collects on the top surface of the tailgate and cascades off when you close it. One thing though - our chrome trim was dealer fitted, not done at the factory. No evidence of any film there though.

 

[ringway]

Ours has never done this - and the tailgate is left open frequently when it's raining! The water collects on the top surface of the tailgate and cascades off when you close it. One thing though - our chrome trim was dealer fitted, not done at the factory. No evidence of any film there though.

Yes, I've seen the doggy photo's with your tailgate open.

Because my vehicles are on a locked driveway, I often leave the tailgates open just to air the interior (for some reason).

That your trim was dealer-fitted may be an important point, Bill. I had heard when I first started my warranty claim that the trims were over-tightened at the factory. Perhaps a revision in torque setting or a tech with a deft touch?

 

[zenman63]

Well my Dec 28, 2007 Viano has the very same rust spots.
Not gone to my Dealers about it yet but I will give it a go, very doubtful as it's from the outside, I have 3-4 small scabs the same as ringways.
I have had the rear door card off and its mint inside.
This Viano has full MB history with the box ticked that says body corrosion checked.

 

[ringway]

Well my Dec 28, 2007 Viano has the very same rust spots.
Not gone to my Dealers about it yet but I will give it a go, very doubtful as it's from the outside, I have 3-4 small scabs the same as ringways.
I have had the rear door card off and its mint inside.
This Viano has full MB history with the box ticked that says body corrosion checked.

I can't say I'm pleased to here about your rust spots, Zenman but at least I'm not alone, now.

It would be very interesting to see where the corrosion is on your Viano as this would enable us to compare notes to see if there's a pattern to the problem.
IIRC, my Vito was 3, years and 4 months old when I first noticed the problem.


Why not add some images to my thread HERE and hopefully some good can come from it.

 

[Arthur13]

Iv had the same issue as this on my 2007 Vito, iv found out that the water has been coming in from the break light on the top of tailgate, Nothing a bit of clear silicone couldn't sort!