Borrowed your idea and have just fitted 4mm foam cord into my seals and on first test it seems to have done the trick.
I need too wait for it to be dry and warmer until I seal up my detached drain though.
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Leaking Kombi Windows? How-to guide to resolve.
- Thread starter DaveyB
- Start date
Borrowed your idea and have just fitted 4mm foam cord into my seals and on first test it seems to have done the trick.
I need too wait for it to be dry and warmer until I seal up my detached drain though.
Sealed up my detached drain on the drivers side window a couple of days ago and it's better - but treated today and it was still leaking from one bit, right behind the drain bottom cover. Sealed up with some more sikaflex 522 and hopefully that'll be it done. It's a right pain to get too, so I've sealed around the drain rather than trying to seal between the plastic parts. Some water did come out the correct hole outside below the window so I'm confident it'll work once it's been fully sealed.
Right then.
"New (old) and improved™" window seals with 4mm foam cord inserts, fitted fully to both sliding windows.
Drivers side front drain now fully sealed, had to seal up new leaks twice after the first application of sealant.
And... Success.
The drivers side is now now longer leaking at all down the inside of the door panel. It's somehow getting in between the main glass frame and the door which does mean the water is draining into the door handle catch and out the bottom drain via the pipe, as well as draining from the exterior drain... BUT no water is getting inside. Which is the main thing!!
I've just doused the windows in about the average rainfall for a UK summers day in 5 mins, and apart from a tiny bit of water on the upright front section on the drivers side (which will drain like the water from the main drain hole) it's watertight!!!
"New (old) and improved™" window seals with 4mm foam cord inserts, fitted fully to both sliding windows.
Drivers side front drain now fully sealed, had to seal up new leaks twice after the first application of sealant.
And... Success.
The drivers side is now now longer leaking at all down the inside of the door panel. It's somehow getting in between the main glass frame and the door which does mean the water is draining into the door handle catch and out the bottom drain via the pipe, as well as draining from the exterior drain... BUT no water is getting inside. Which is the main thing!!
I've just doused the windows in about the average rainfall for a UK summers day in 5 mins, and apart from a tiny bit of water on the upright front section on the drivers side (which will drain like the water from the main drain hole) it's watertight!!!
I say shame on VW, they should put this right!The replacement non OEM windows are no good for me either as with a caravelle the slider rails fit closely into the interior door trims so I'd need to change them too.
It's obvious that VW know the design is shite (ignoring the rust in the upper sliding section, that's a while other issue!) as they've 'designed' 2 ways of water to escape when it gets past the seals. It's just that those 2 ways are crap!!
So the first line of defence in the ongoing war against water, is to make sure your seals are clean and well lubricated with silicone grease or similar.
If the seals fail, then it's the job of the 2 narrow drain slots to get rid of the water.
If they fail then the final line of defence is the round drain holes and underlying flimsy plastic held on with soft sealant, that eventually fails if you happen to look at it wrong!!
I'm now on stage 3, my front round drain was blocked meaning water over the door card when the first 2 lines of defence were broken, but recently that drain has become unblocked and detached which means a waterfall inside the door card.
I've got some sikaflex coming tomorrow and will try to seal it back up whilst also leaving it not quite pushed against the drain hole, or else water doesn't drain from it!!
I've confirmed that it "works" by squirting water inside it from the bottom to make sure it's exiting from beneath the window, which is is. So I just need to seal it up properly.
The main issue I see are the seals, which don't seal that well! Hence why I've added the foam core to mine, which seems to have improved the seal massively.
The drains work, so long as they're not blocked or broken, but they're only there in case the seal fails so if the seals worked then the drains wouldn't need too deal with much water.
I'm really not sure, given how common an issue this is, why someone hasn't reverse engineered the seal and improved it by making it filled with foam, or out of a slightly firmer rubber, or slightly bigger. Oh and being able to buy the seals on their own would be massive advantage!
It's like having a toddler who wets the bed, these vans 
Rained overnight. 'Are we dry this morning? Oh, yes we are! Whos a good van!! Yessss, you are!"
Rained overnight. 'Are we dry this morning? Oh, yes we are! Whos a good van!! Yessss, you are!"
Hi everyone , a little bit late to the party here … just got my first t6 back in December and was delighted to find that kombi sliding window on on the sliding door look leaked like a sieve .
Big thanks to @DaveyB for the guide to remove the sliding window glass and to everyone else that has contributed to this thread.
So far I’ve had both windows out , cleared the rectangular slits front and rear against the glass, thoroughly cleaned the rubbers , silicone sealed around the lower part of the round drain holes , applied silicone grease to the seals and checked each of the areas as reasonable as possible using a syringe to direct the water .
All tests seemed positive and I could clearly see water exiting where intended so reassembled and waited for it to pee down …
Didn’t take long for that to happen …
This seemed to have done the trick and several days of rain with none inside the van was looking like a result however after driving the van whilst it was raining a small amount still managed to get through .
I don’t really want to replace the windows if I can get away with it and also would like to retain the opening feature of them ,or else I’d consider as others have already done , using silicone to seal them permanently shut .
Also as a process of elimination I had previously used insulation tape around the gap between the fixed and opening part of the glass just to prove to myself that this was the point of entry of the water , which I’m pretty confident is the case with mine .
This and the earlier post from @tomek12 and also @TallPaul_S has lead me to purchasing some sponge cord in 3mm diameter and 6mm diameter to insert in the gap between the two pieces of glass … the rear vertical section is wider at 6mm than the top , bottom and front which are around 3mm .
I figured this would kind of ‘winterise’ the window until the weather picks up without it being permanently sealed shut with silicone. Seems to be doing the trick at the moment and I thought it might help someone that’s struggling with the same issues as a quick and easy temporary measure whilst the weathers not great.
From the outside you can hardly notice anything different , just need to remember to remove it if your gonna open the window and remember to replace afterwards .
Big thanks to @DaveyB for the guide to remove the sliding window glass and to everyone else that has contributed to this thread.
So far I’ve had both windows out , cleared the rectangular slits front and rear against the glass, thoroughly cleaned the rubbers , silicone sealed around the lower part of the round drain holes , applied silicone grease to the seals and checked each of the areas as reasonable as possible using a syringe to direct the water .
All tests seemed positive and I could clearly see water exiting where intended so reassembled and waited for it to pee down …
Didn’t take long for that to happen …
This seemed to have done the trick and several days of rain with none inside the van was looking like a result however after driving the van whilst it was raining a small amount still managed to get through .
I don’t really want to replace the windows if I can get away with it and also would like to retain the opening feature of them ,or else I’d consider as others have already done , using silicone to seal them permanently shut .
Also as a process of elimination I had previously used insulation tape around the gap between the fixed and opening part of the glass just to prove to myself that this was the point of entry of the water , which I’m pretty confident is the case with mine .
This and the earlier post from @tomek12 and also @TallPaul_S has lead me to purchasing some sponge cord in 3mm diameter and 6mm diameter to insert in the gap between the two pieces of glass … the rear vertical section is wider at 6mm than the top , bottom and front which are around 3mm .
I figured this would kind of ‘winterise’ the window until the weather picks up without it being permanently sealed shut with silicone. Seems to be doing the trick at the moment and I thought it might help someone that’s struggling with the same issues as a quick and easy temporary measure whilst the weathers not great.
From the outside you can hardly notice anything different , just need to remember to remove it if your gonna open the window and remember to replace afterwards .
Haha, that's an interesting solution! I would highly recommend trying to insert the foam cord into the seals though, mine are still lovely and dry!
All it does is make a better seal against the window - they're no harder to close so that helps me the seal really isn't great to begin with.
Silicone grease is great and will also make them seal better but 1. It gets washed out and runs down there van, and 2. It doesn't last for ever.
All it does is make a better seal against the window - they're no harder to close so that helps me the seal really isn't great to begin with.
Silicone grease is great and will also make them seal better but 1. It gets washed out and runs down there van, and 2. It doesn't last for ever.
I think I will give your solution a go to be honest , I just need to order some 4mm …
Should prob have ordered some at the same time as the other sizes now I think about it
Was it easy enough to thread it inside the seals ?
Easy-ish.I think I will give your solution a go to be honest , I just need to order some 4mm …
Should prob have ordered some at the same time as the other sizes now I think about it
Was it easy enough to thread it inside the seals ?
I used a spare bicycle gear cable to thread though, then tied the cord on. Plenty of lube (I used wet bicycle chain lube), and pull it back through. I needed too do one in 2 parts at the friction gets higher the more you pull through, and the cord will probably snap. I just cut a tiny slit to feed the 2nd part then glued them up with super glue.
You won't be able to push it through, you'll need something to pull it back through, and the straighter you can have the seal the better to reduce friction.
Ok great, thanks for the advice !
I’ll get some ordered and wait for a bit of decent weather to give it a go !
Cheers
So my windows are still nice and leak free, well - almost.
On my driver's side window (which was the one leaking the most and on which I fixed the drain) I was noticing a few droplets on the lower half of the front of the sliding part, just behind the plastic 'guard' running vertically.
We had a load of rain and wind last night and this morning there was a few more drops as I'd cleaned off the silicone grease on the seal.
Now, inspecting the other side window from the outside, I realised the gap, when closed, between the front of the sliding part and the fixed part was bigger on the drivers side. Confirmed by looking at the rear of the window and the dots printed on the window - it was probably around 2-3mm further back.
Giving the drivers side a good shove when closed seems to have helped, but then I remembered when taking the window out, one of the locking pins was broken - one of these
They have a plastic cover over the metal rod, and on removing mine, the lower one was indeed broken, with the broken bit at the rear. This I think is the cause of the window not pushing forward as much when closed and therefore not sealing as well as it should! The top one was also a bit worn.
I've just ordered a window repair kit off eBay for £8 which includes the rods. That should finally sort the very last bit of water that's finding it's way in!!
So that's another thing to check if your windows are still leaking!
On my driver's side window (which was the one leaking the most and on which I fixed the drain) I was noticing a few droplets on the lower half of the front of the sliding part, just behind the plastic 'guard' running vertically.
We had a load of rain and wind last night and this morning there was a few more drops as I'd cleaned off the silicone grease on the seal.
Now, inspecting the other side window from the outside, I realised the gap, when closed, between the front of the sliding part and the fixed part was bigger on the drivers side. Confirmed by looking at the rear of the window and the dots printed on the window - it was probably around 2-3mm further back.
Giving the drivers side a good shove when closed seems to have helped, but then I remembered when taking the window out, one of the locking pins was broken - one of these
They have a plastic cover over the metal rod, and on removing mine, the lower one was indeed broken, with the broken bit at the rear. This I think is the cause of the window not pushing forward as much when closed and therefore not sealing as well as it should! The top one was also a bit worn.
I've just ordered a window repair kit off eBay for £8 which includes the rods. That should finally sort the very last bit of water that's finding it's way in!!
So that's another thing to check if your windows are still leaking!
@TallPaul_S I’ve been thinking about an insert for the OEM seal for a while now. My plan was to get a used / failed window and not test on my own van.
I was planning on cutting a small slit near the top of the seal on the vertical run and threading some PTFE rod around the seal in one single length before superglueing the slit closed.
I’m thinking that the PTFE rod would plump out the seal, resist compression and be stiff enough push through around the corners with the low friction properties of PTFE.
Do you think its worth a shot?
Yeah that sounds like a plan - my windows are still 99.8% watertight, just the very odd drop on the vertical front side of one.
I think making the seals, seal better is the best first step, if I could get a firmer seal with a bigger foam insert I would have done but getting it in was the issue as the friction increased.
I’ve looked on Ebay and there are plenty of silicone rubber seal profiles available by the meter.
I just need a donor window to experiment on instead of my own van
Started my own thread on this as my driver's side slider is leaking, a combination of the the water catch being detached and water getting in past the seals.
Sliding door leak inside door panel
I've got water coming in from somewhere in my driver's side sliding door, which is running down and ending up sitting on the seal around the door step, like this: Which looked like this when I removed the door card, side step and seal: Now, I do have sliding windows, and the little catch...www.t6forum.com
But thought I may as well add to the knowledge here
Whipped out the window (thanks to the guide in the OP) and removed the seal to find rust on the top section of the sliding unit.
View attachment 230062
Seems this is a common place for it to rust!
My passenger side isn't leaking but I'll probably need to check this for the rust too.
I gave the seal a good coating of silicone grease, wiped off the excess and it looks like it's now sealing as no water is getting in to the channel, so that's one thing. Just the water catch to re seal.
Edit: took out the passenger window too and this has started to go. Not as bad as the drivers side though.
View attachment 230070
There's blatantly some sort of design flaw here, but I doubt VW will admit that. However, I don't think the rust in the seal channel is the cause of the leak, as my passenger one has never leaked as far as I can see. Gave the seal a coat of silicone grease and worked a feeler guage into the drain slots anyway.
Hi @TallPaul_S, I've just take out my driver side slider to try and fix the leak (has it taped up for a couple of months) and have the same rust issues as your pictures. I've given it a spray with wd40 and tried to clean it up a bit. I've attached a picture - is the bottom of the frame supposed to follow that shape/contour, or has the rust caused that?
I can see from your later messages that you seem to have pretty much repaired your windows from that state by adding in 4mm cord into the seal (which I've just done while I have the window out) and rebonding/dealing the flap that has come away below the circular drainage hole?(which is my next job!)
What did you do about the rusted bit, did you just try and clean it up as much as possible? Any advice?!
I do have the All-in policy, but other messages seem to suggest limited chance of success getting it repaired/replaced under that (especially now I've stuffed the seals!) and I'm not prepared to pay the £140 diagnostic fee only for them to say its not covered...
Any other pointers (particularly about dealing with the rust) would be appreciated.
I haven't done anything about the rusty bits - I think it's a separate issue to the leaking and if/when it gets any worse I'll probably end up replacing the sliding part of the window.
It's obviously water that sits in the seal groove (mine were rusty at the top) which can't escape which over the years causes it to rust. I'm not sure if this is the correct part but it does look like you can find them brand new:
And yes, my windows are still leaking free - maybe a droplet or 2 in days worth of rain but considering I had a small swimming pool there previously I'm more than happy with that!
It's obviously water that sits in the seal groove (mine were rusty at the top) which can't escape which over the years causes it to rust. I'm not sure if this is the correct part but it does look like you can find them brand new:
VW TRANSPORTER T6 Right Side Sliding Door Tinted Glass 7E0847796E NEW GENUINE | eBay
TRANSPORTER VI (T6) Flatbed (SFD, SFE. Genuine parts. All of our parts are new & GENUINE! Part number. ).
www.ebay.co.uk
And yes, my windows are still leaking free - maybe a droplet or 2 in days worth of rain but considering I had a small swimming pool there previously I'm more than happy with that!
I would not bother trying with the warranty. I did and got absolutely nowhere. I ended up replacing with a fixed OEM glass panel.
I do still have the whole failed unit and happy to give to anyone who wants to try a fix. I am away in the van until mid July. Happy to work something out if you can do anything with the old unit.
I do still have the whole failed unit and happy to give to anyone who wants to try a fix. I am away in the van until mid July. Happy to work something out if you can do anything with the old unit.
I haven't done anything about the rusty bits - I think it's a separate issue to the leaking and if/when it gets any worse I'll probably end up replacing the sliding part of the window.
It's obviously water that sits in the seal groove (mine were rusty at the top) which can't escape which over the years causes it to rust. I'm not sure if this is the correct part but it does look like you can find them brand new:
VW TRANSPORTER T6 Right Side Sliding Door Tinted Glass 7E0847796E NEW GENUINE | eBay
TRANSPORTER VI (T6) Flatbed (SFD, SFE. Genuine parts. All of our parts are new & GENUINE! Part number. ).www.ebay.co.uk
And yes, my windows are still leaking free - maybe a droplet or 2 in days worth of rain but considering I had a small swimming pool there previously I'm more than happy with that!
Yup, I've just noticed that the rusted but is at the top. I had just assumed it was at the bottom, so assume that water must just lie on top, as you say.
Think I'll just try and clean it all up as well as I can, fit the plumped up seal and try and make sure I completely fix the leaky drain bit (which I think I made worse when initially trying to "clear" it by pushing down on it from top!)
I'll post an update with how it all goes in case it helps anyone else.
