Leaking Kombi Windows? How-to guide to resolve.

[Tommy]

highly frustrating and I feel your pain. I would hazard a guess at the windows leaking. water on the step was a tell tale sign I had. I ended up going to check the van when raining but entering through the cab rather than open the sliding door to rule out any drips when opening.

Have you had a go at fixing them yourself first?
I was all set to have mine replaced with aftermarket but glad I managed to fix them. It really isn't as daunting task as it looks taking them apart.
It was looking around £500 to replace them (1 flush slider 1 fixed all installed by another company). Loads of information above. Another reason to fix and keep the OEM is that they look the best with flush sliders, in my opinion.

Regarding longevity, the main reason, based on my own experience and extensive forum research, is that the windows leak for two reasons 1) the drain holes are blocked with sealant when the window was installed (unbelievable I know) and 2) the glue on the little plastic tab under the drain hole on the inner runner is poor/ debonds causing a leak at this point. When you have sorted both of these items I don't see (fingers crossed) it being a long term problem. I keep a radio key in my glove box and periodically poke it down the drain holes to ensure they are clear, its a 2 second job and you don't need to remove the glass to do so.

Hope that is some help. for the money its got to be worth a shot having a go! worse case you get them replaced anyway...!

Thanks David I need to have a little read up on the various threads before attempting especially if you have to start removing trims etc and foremost if I can retain original sliders then £500 in the back pocket - that's got to be Asda price for sure

 

[david173]

Thanks David I need to have a little read up on the various threads before attempting especially if you have to start removing trims etc and foremost if I can retain original sliders then £500 in the back pocket - that's got to be Asda price for sure

The first post is really good at explain how to remove the trims etc. the rest of the thread contains all the info and tips on sorting it out. best of luck!

 

[Scruffy]

I've just gone back to the OP and its brilliantly explained, but as a short cut I use a can of compressed air and a straw and blast the drain holes clear a couple of times a month and it seems to do the trick. I do it more frequently in the winter.

 

[JonriceT6]

Buy windows that don’t open, go for plain glass. A lot of people have replaced kombi windows with plain glass.

 

[Cuiken]

Just bought our first Van. Twin slider Kombi. First day of rain and, yep, both windows leaking like seizes.

It's past its warranty though so trying to figure out how to sort this myself.



Bit of investigative work tells me that:

1. The drainage hole next to the red arrow is not blocked. If I syringe water into this hole, most of it runs down the ourtside of the door. Yeah, 'most of it'. Some finds its wat down the inside of the door. I'm thinking though that this drain is secondary to the slot drain highlighted in yellow.

2. The thin 'slot' in the window runner channel (highlighted in yellow, shown with a tool inserted for cleaning) is not blocked and water injected here finds its way to the outside of the door without any leaking inside the door.

3. The interesting thing is that, while the window is busily leaking, neither of the drain holes (marked 1 and 2) have any water around them at all. I'm fairly sure the issue is that the water is simply finding it's way between the seal where the slider assembly is bonded to the window. I've attempted to highlight this in green. So, none of it actually reaches the drains anyway.

I mean, wow, don't these windows have a multitude of exciting ways to fail?

Anyway, looks like my best shot is to do two things:

Remove the sliding window and clean the rubber seals on the sliding window itself. Hopefully this will at least reduce the amount of water coming in. The seals are very dirty so I suspect this will help a bit.

Then I need to improve the seal where the slider assembly is bonded to the glass. I'm going to try the 'Captain Tolley’s Creeping Crack Cure' product mentioned in a previous post. If that fails then I'll move up to proper glass bonding product.

Hopefully, at that point any water that does get in will at least find its way to the drains and I can start to debug the next bit of the puzzle!

Anyone got any thoughts on the approach I'm proposing here?

Thanks

 

[DXX]

Just bought our first Van. Twin slider Kombi. First day of rain and, yep, both windows leaking like seizes.

It's past its warranty though so trying to figure out how to sort this myself.

View attachment 129665

Bit of investigative work tells me that:

1. The drainage hole next to the red arrow is not blocked. If I syringe water into this hole, most of it runs down the ourtside of the door. Yeah, 'most of it'. Some finds its wat down the inside of the door. I'm thinking though that this drain is secondary to the slot drain highlighted in yellow.

2. The thin 'slot' in the window runner channel (highlighted in yellow, shown with a tool inserted for cleaning) is not blocked and water injected here finds its way to the outside of the door without any leaking inside the door.

3. The interesting thing is that, while the window is busily leaking, neither of the drain holes (marked 1 and 2) have any water around them at all. I'm fairly sure the issue is that the water is simply finding it's way between the seal where the slider assembly is bonded to the window. I've attempted to highlight this in green. So, none of it actually reaches the drains anyway.

I mean, wow, don't these windows have a multitude of exciting ways to fail?

Anyway, looks like my best shot is to do two things:

Remove the sliding window and clean the rubber seals on the sliding window itself. Hopefully this will at least reduce the amount of water coming in. The seals are very dirty so I suspect this will help a bit.

Then I need to improve the seal where the slider assembly is bonded to the glass. I'm going to try the 'Captain Tolley’s Creeping Crack Cure' product mentioned in a previous post. If that fails then I'll move up to proper glass bonding product.

Hopefully, at that point any water that does get in will at least find its way to the drains and I can start to debug the next bit of the puzzle!

Anyone got any thoughts on the approach I'm proposing here?

Thanks

My findings with my leaking near side slider;
1. Directly below this ‘hole’ is a thin plastic flap that is glued onto the plastic frame with a non-hardening adhesive. If anybody has poked something down this hole it will almost certainly of disturbed the sealing and will need re-working. This sounds like a simple job but it took multiple attempts to repair mine, access is achieved by pulling off the lower plastic trim. This drain joins the rubber tundish that collects all of the water that gets in through the door catch and it eventually drains out of the bottom of the sliding door via a hose and rubber grommet in the door skin.

2. This slot needs regular cleaning, I found that a smear of washing up liquid in the channel leading to it breaks the water surface tension and increases the drain rate.

3. It is possible to clean the seals without removing the window, I use a flat steel rule with a wipe taped on.
Don’t use petroleum distillates which will perish EPDM.
Once clean I ‘plumped‘ mine up with a good rub of silicone grease, this can get messy and it’s important to remove almost all of the surface grease as the next coating of road dirt will stick to it.

If at any point you get to having all three items working as they should sit back and crack a beer.
If you only have 2/3, persevere and learn new German swear words.
If you only have 1/3, pull your f’kin finger out, winter is coming.

 

[Cuiken]

Thanks. The thing is though that the drains on mine are doing nothing because the water just pees down between the glass and the slider assembly (green line). It never makes it as far as the drains. Basically, I'll only ever get 1/3

Hopefully either the Captain Tolley's stuff or, worst case, silicone will help fix that seal and then I can try to figure the drains out.....

 

[DXX]

Thanks. The thing is though that the drains on mine are doing nothing because the water just pees down between the glass and the slider assembly (green line). It never makes it as far as the drains. Basically, I'll only ever get 1/3

Hopefully either the Captain Tolley's stuff or, worst case, silicone will help fix that seal and then I can try to figure the drains out.....

If you can’t fix it now I would tape it rather than silicone. Tape takes seconds to remove and give the repair another attempt. Silicone sealant will be difficult to remove if properly cleaned before application.

 

[Ali-G]

Try cleaning and treating the seals first, this has stopped mine leaking.
I just cleaned them with a damp microfibre cloth and then when dry I applied Gummi Pflege. I didn’t remove the windows.

 

[Cuiken]

Try cleaning and treating the seals first, this has stopped mine leaking.
I just cleaned them with a damp microfibre cloth and then when dry I applied Gummi Pflege. I didn’t remove the windows.

Thanks, yes orderd my Gummi Pflege yesterday. Turned up today. Two observations:

1. It's petroleum jelly (vaseline). So seems to fly in the face of concerns raised about degrading the rubber. That said, it claims ot be precicely for the application that it's being used for here. Is vaseline so bad?

2. It smells like a chapstick. Have I just paid £10 for an oversized lypsol?

Cheers

 

[Cuiken]

If you can’t fix it now I would tape it rather than silicone. Tape takes seconds to remove and give the repair another attempt. Silicone sealant will be difficult to remove if properly cleaned before application.

Good suggestion. It'll be fiddly to install but would definitely be a useful proof of concept. I guess simple insulation tape would be the best shout.

 

[Ali-G]

1. It's petroleum jelly (vaseline). So seems to fly in the face of concerns raised about degrading the rubber. That said, it claims ot be precicely for the application that it's being used for here. Is vaseline so bad?

I had no idea, I’ve never looked at the ingredients.
I’ve been using it for years on all my vehicles.

 

[oldiebut goodie]

Cleaning and silicone grease on the seals with Captain Tolley's Creeping Crack cure applied at the top certainly stopped my leak - we have had several deluges since doing it and not a single drop has made its way through. Cotton buds to clean and grease the seal was all I did - no need to dismantle anything.
On mine I think that the bonding was allowing water through somewhere because applying it at the top outside allowed it to exit on the inside. Still cured after 7 months or more!

 

[Cuiken]

Cleaning and silicone grease on the seals with Captain Tolley's Creeping Crack cure applied at the top certainly stopped my leak - we have had several deluges since doing it and not a single drop has made its way through. Cotton buds to clean and grease the seal was all I did - no need to dismantle anything.
On mine I think that the bonding was allowing water through somewhere because applying it at the top outside allowed it to exit on the inside. Still cured after 7 months or more!

@oldiebut goodie Thanks, just for total clarity can you confirm where you applied the Captain Tolley's stuff?

Would it have been along the seem between the glass and the slider assembly (as I've tried to draw in green here)?



I'd never heard of this particular sealent but it seems ideal for this task.

Cheers.

 

[oldiebut goodie]

No - outside between the glass/bonding/bodywork at the top. Using a syringe and a needle you can direct it at the two surfaces. The Captain Tolley's came out inside in the area of the base of the latch mechanism cover. ( I still have a very thin white line where it exited )
Applying sealant inside is a shutting the stable door after the horse has bolted type of scenario, it needs tackling from the outside first to deal with the first point of ingress.
It is time consuming as it runs very quickly through any tiny gap due to capillary action. You have to have plenty of mopping up rags/kitchen roll to prevent it running down the bodywork as it moves everywhere.

 

[Cuiken]

No - outside between the glass/bonding/bodywork. Using a syringe and a needle you can direct it at the two surfaces. The Captain Tolley's came out inside in the area of the base of the latch mechanism cover. ( I still have a very thin white line where it exited )
Applying sealant inside is a shutting the stable door after the horse has bolted type of scenario, it needs tackling from the outside first to deal with the first point of ingress.
It is time consuming as it runs very quickly through any tiny gap due to capillary action. You have to have plenty of mopping up rags/kitchen roll to prevent it running down the bodywork as it moves everywhere.

Okay, got you now. So your issue there was the bonding of the outer section of the window to the bodywork. Not just the seal of the sliding section. I'd not even considered that as a failure point.

Ta

 

[DXX]

Good suggestion. It'll be fiddly to install but would definitely be a useful proof of concept. I guess simple insulation tape would be the best shout.

I used insulation tape between fixes in dry weather, it’s not fiddly. I put it on to keep the rain out not to look good, less than a minute.

 

[oldiebut goodie]

Okay, got you now. So your issue there was the bonding of the outer section of the window to the bodywork. Not just the seal of the sliding section. I'd not even considered that as a failure point.

Ta

Either bond to bodywork or bond to glass, hard to tell that is why the needle needs to be situated on both sides of the bond. I have had a close look at where the bonding is to the glass in other places and can see bits where I think the bond isn't 100% but I am not certain.

 

[boxelder]

Both the drain holes you highlight take water down into a 'reservoir'. The lid on the reservoir is stuck on badly with non setting sealant, which leaks. Pop the plastic trim off below the slider and you'll see it. Carefully seal all around that. Doing that and removing the sliding bit to clean and treat the seals has kept mine leak free for over a year now. The driver's side has furniture, which I didn't want to risk getting wet, so I removed the catch and sealed the slider up from the outside with black sealant.

 

[MikeB]

Buy windows that don’t open, go for plain glass. A lot of people have replaced kombi windows with plain glass.

I tried all the various ideas and suggestions before we did. Bliss - no leaks - - and no more concerns about the furniture on the drivers side being ruined, water getting under the floor, damaging the wiring for the pump / batteries / heater. (All of which I'm told have happened!) My advice? Put in plain glass - if you are spec'ing a Kombi from new, I hear it may be possible to spec with plain glass, so it's worth asking.