View Full Version : Leaking windows in front doors Causing rust on bottom of door.

02-13-2013, 10:43 AM
Hi all

On my 04 Sprinter the door to window seals on the outside of the door dont quite meet.
At the sealing edge along the bottom of the window there is a very small gap between the seal and the window, probably about - a millimetre.
While not very big it is large enough from water to run down the inside of the door, this is causing the seam on the bottom edge of the door to start to rust.

Obviously MB have designed the door to take account of this leak as there are a lot of drainage holes along the bottom edge of the door.

But I should be able to get them to seal better than they do at the moment????

I have tried taking the whole thing apart and reassembling it several times.
I have also tried a new MB outer sealing strip.
Moving the window guide rail as far outwards as I can.
Tweeking the door skin that the sealing strip mounts to.

All of these made the gap smaller, but it is still there and still leaking.

Anyone got any other ideas, apart from sealing the window shut!!!! :dripsarcasm:

Thanks Dave

Altered Sprinter
02-13-2013, 10:55 AM
Seems the rubber seal on the outside window is not matching to the inner felt seal on the inside lower section ,just below the window frame..replace both.
If that's the problem

02-13-2013, 11:02 AM
I am kind of doubting any rubber trim piece is going to be water tight, that is why they put the holes on the bottom of the door, the trim is made of rubber so it does not scratch the glass. Your Sprinter is rusting, just another statistic?

Altered Sprinter
02-13-2013, 11:12 AM
Is rust that brown stuff:tongue:

02-13-2013, 11:27 AM
Is rust that brown stuff:tongue:

Actually my T1N has a lot of rust near the bottom of the passenger door and very little on the drivers side, well opposite on the other side of the equator? :tongue:

Any ways, most likely the seam had some corrosion from the get go, or it was not properly sealed, no way to stop rust once it has started, cut it out or get a new door? :idunno:

02-13-2013, 12:32 PM
Hmm, I have reskinned the passenger door so dismantled that seal several times and don't recall noticing a gap/leak between the seal and the window, I'll have to try and take a look later.

The front lower corner doesn't sit very tight against the steel/paint, I welded a bit of flat bar behind the hole I had there and filled it flush. The bottoms of all my doors are rusting out (except the passenger door which has a new skin from about 4" below the door handle down) and they don't all have windows so I think water collects there even if you don't have a leak!

You say you have moved the guide channel out as far as possible - have you secured the lower end with screws or left them out so you can ease the glass out again next time (I may have left mine out.... can't remember!), if so maybe check the regulator arm is not bent and pulling the glass and channel away from the door.

Hang on, Richard might have it - you only mentioned the rubber seal - do you have one or 2 seals outside of the glass? There is one that pushes onto the edge of the regulator cage for the inside, the solid rubber one fixed in the door frame, and I'm sure there another one just along the lower edge between the rubber outer seal and the glass which I don't think is very securely held - like if it sticks to the window and your passenger winds the window up without noticing it could lift out and fall away..... or have I imagined that?

I should have some photos from re-skinning the door, unless they were on my laptop when it hung up and had to be reinstalled at xmas because I hadn't got round to backing it up. I didn't do it the best way but I could do a write up including how I will do it differently next time - drivers and side door definitely need doing, rear doors are putting on a reasonably good show but I suspect the bottoms are entirely made of filler!

02-15-2013, 02:11 AM
Nope, just the rubber seal on the outside of the glass, felt one is inside.

My passenger side is exactly as you describe (I only got round to putting the door card back on last week, now I need to check behind it!) with a gap along the bottom (not the sides though. The divers side is touching along the bottom. Hmm, I did say I may have forgotten to put the lower screws back in the guide channel, wonder if it is that?

02-15-2013, 11:12 AM
Nope, just the rubber seal on the outside of the glass, felt one is inside.

My passenger side is exactly as you describe (I only got round to putting the door card back on last week, now I need to check behind it!) with a gap along the bottom (not the sides though. The divers side is touching along the bottom. Hmm, I did say I may have forgotten to put the lower screws back in the guide channel, wonder if it is that?

So boater, you had the doors all apart, are they actually water proof, of just a tight fit? I could not see that rubber seal around the door stopping all water, unless it was like your windshield, a non operable window? BTW, I have rust around the windshield rubber as well.

And yeah, all of my doors with out windows have rust as well, water does not cause rust, poor prep, and lack of coatings, or poor coatings cause rust.

02-15-2013, 12:28 PM
I have only had the passenger door apart, and my welding of the edge of the new door skin may have warped it (next time I'll flange it and discreetly plug weld it using filler to fill the gap, and seam sealer on the back).
I don't know how effective the seals are, a hose test on a tight one is probably required!

Don't ask about the windscreen, it doesn't seal against the steel so water will get in at the top and spread by capilliary action. I honestly don't know how to repair that, it will take more than 1 day. I'll probably need to shape a couple of bits of ply to screw together either side of the frame to secure the van whilst the screen is out. How much pressed steel will need to be cut out and replicated I don't know, for now I have treated it to slow it down!

You are kind of right that water does not cause rust, but electrolyte is needed and bare dry steel won't rust, so it is definitely a causal influence. Pretty sure that condensation on the sides will run down to the sills and door bottoms creating a nice electrolytic environment to exploit any coating anomolies. Oxygen is also needed in the reaction, completely immersing something in water without oxygen (there is dissolved oxygen in most water, that's how fish survive) would stop it rusting, although if electrolytic you would presumably get migration from anodes to cathodes within the steel....???? Woah, getting into the science of corrosion now - that's for others to work out!

02-16-2013, 10:06 AM
Thanks for the replies.

I am sure the seal is not meant to be 100% water proof as its a felt type seal not a rubber windscreen wiper type seal. But I do think it should be better than it is.

Bolater: Good idea about checking the end of the lever that moves the window. I will take the door panel off and check this in the next couple of days. As for the screws for the guide rail I have put them all back in. I ended up having to redrill them to keep the guide rail in the new position.


05-25-2015, 02:08 PM
I have rebuilt doors for a Sprinter and noticed the terrible "seal". Not only does it lack any kind of water protection but the tolerance is zero. Almost hard to not laugh the rubber seal is on the inside. I had a gap of 5 mm on one door and the other was 0-2 mm. I checked both my Sprinters and the original doors of my 1997 and the 2004 had the same gap.

Not only is the seal a bad construction but the whole construction inside the door. The handle put all load onto the window mechanism which flex, specially the upper fixture of the handle. Some of that load is transfered to the window which will pull the guides every time you close the door, specially if you close it by dragging the door that last bit.

I fixed mine by removing the panel and dumping som washing sponges in the door sill. Then I removed the mechanism and carefully dropped the window as far as possible making sure it wouldn't notice if I abused the door. I used a hammer and a piece of oak (W ~4cm x H ~0,8cm) from the outside right onto the seal as it was. I also hammered a chisel from the inside onto the inner and outer part of the window guide. Most at the height of the seal but eased out going up/down 10 cm. Every now and then I tried to lift the window to monitor my progress. It's firm from the point of taking on the seal but not too much. I also left with a 1 mm gap in the rear corner as that is easy to adjust with the door completed. You don't want to work on the seal in the front half when the window mechanism is in place. In total it was 10 min of hammering. I also adjusted the mechanism arm with the rear part of my construction-hammer, but only so it would be unloaded sideways during the whole scope of operation. (See the other thread where this joint breaks and people has to replace it with a rolling wheel from a shower cabinet)

I'm sure this is the reason all Sprinters have rusty doors as the window is actually a funnel leading the water into the door. I will try to find a U-seal like the original that keep the window from wobbling but with a foam roll or foam roll + rubber wing that will clear even a 5 mm gap. If anyone has experience or found a better seal - please let us know. There must have been a transition going from the 40'th until todays rubber wings. Remember the foam seal anyone? Kept flapping up/down with the window and there was always leafs that was stuck in between?