Rear window leak

[DarkSky20]

Noticed mine in a touch less car wash. Of course my problem was a foot of sealant wasn’t applied at the factory 

[OnTheReel]

11 hours ago, MG386 said:

Add me to the list, 2020 AT4. Built Nov 2019 in mexico. 17,000 miles. Home garage, and work garage, and live in PHX, so not much water exposure. I'll probably wait a while to see if GM can come up with a good fix.

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Pretty much how mine is now. You can stick some towels down there to absorb it. Since the headliner isn’t getting wet I’m just leaving it. No point in taking it back for another failed repair.

[MG386]

Yea, at this point I'd rather deal with a few drips. They're not touching the headliner(yet). And I really don't want dirty mechanic fingerprints all over my pillars and liner.

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[Kclyatt]

On 3/6/2021 at 9:59 AM, MG386 said:

Yea, at this point I'd rather deal with a few drips. They're not touching the headliner(yet). And I really don't want dirty mechanic fingerprints all over my pillars and liner.

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Give my diy repair a try...scan back couple of pages for pics. I’m leak free 5+ months now!

[2016 Sierra Owner]

On 3/4/2021 at 11:30 AM, DSW1519 said:

TSB Sealing Repair Completed – UPDATE

 

Quick background – Picked up my ’21 Sierra on 12/4/20. Within 10 days of ownership I had the leak on both sides at the top of the slider. Dealer completed the TSB, and I could see a heavy bead of the sealer that was laid across the top frame of the slider.  After the TSB was done I didn’t see any leaks and continue to check very closely after every rain. I have a small towel sitting on top of the rear seat back rest just in case the slider starts leaking again. About a month ago during a steady rain I saw a drop of water from the same location - literally a few drips where it was barely leaking, but the towel on the seat back rest was dry to the touch as was the carpeting.

 

As others in this thread have suggested and since it was barely leaking I decided to try the flowable silicone (permatex 81730) rather than have the truck torn apart again. When we had a warm day I cleaned the top of the slider as best I could and also taped off the top of the glass on the slider to try and minimize the mess. I used a full tube of the permatex and made a few passes across the top of the slider frame, being careful to not overfill the area. As other posters have mentioned that have used this product it is thin and runny, so being careful minimizes the clean up.

 

Since using the flowable silicone 4 weeks ago we have had both snow and rain. Over the past week we have had significant rain, including long periods of drizzle, solid rain and heavy down pours. So far no leaks, so the effort was well worth it. I can see along the top of the slider frame where the flowable silicone has dried there is an even layer of silicone across the complete gap. It looks like the permatex product took care of any small gaps that the TSB work didn't completely seal. So far I’m really impressed with the permatex product and will use it again should I see a small leak in the future.

 

Pic below of where it was leaking and also of the permatex product used. Thanks to everyone that recommended this product and the idea.

 

 

Only 1 slight problem with your pic of where the actual leak was. It may have been there but, I'll bet it was actually somewhere else on the window. When Mine was leaking (yellow arrow) the was about 3-4 inches to the left (leak was on the drivers side) of where you are pointing. I actually lifted up the headliner a bit and saw the water coming in. The window track that you see in your picture however acts as a gutter carrying the water (yellow line) to the left or right till it ends. That is what the arrow on your picture is pointing at. The end of the gutter in other words. Now when I had the TSB done at the dealer the leak actually moved from 6-8 inches from the top corner to the water coming in at the very top right corner. (orange arrow) 

 

[2016 Sierra Owner]

On 3/5/2021 at 10:26 PM, MG386 said:

Add me to the list, 2020 AT4. Built Nov 2019 in mexico. 17,000 miles. Home garage, and work garage, and live in PHX, so not much water exposure. I'll probably wait a while to see if GM can come up with a good fix.

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GM is not going to come up with any other solution. Their fix is the TSB to seal the top of the window. If that does not work. The next step is to replace the whole window unit. I just had that done on mine. If it needs to go for a 3rd repair then it's time for me to file a lemon law case. The glass guy told me he did one a few days before where the guy didn't catch the leak in time and when he went to replace the window and removed the back seat. There was an inch of water in his floor board and the truck smelled like mold. I'd get it documented at the dealer that it leaks as soon as I could.

 

[DSW1519]

Only 1 slight problem with your pic of where the actual leak was. It may have been there but, I'll bet it was actually somewhere else on the window. When Mine was leaking (yellow arrow) the was about 3-4 inches to the left (leak was on the drivers side) of where you are pointing. I actually lifted up the headliner a bit and saw the water coming in. The window track that you see in your picture however acts as a gutter carrying the water (yellow line) to the left or right till it ends. That is what the arrow on your picture is pointing at. The end of the gutter in other words. Now when I had the TSB done at the dealer the leak actually moved from 6-8 inches from the top corner to the water coming in at the very top right corner. (orange arrow) 

 

I agree with what you are saying. Where the drip on the inside was located that is the lowest point, so I'm not exactly sure where the actual leak was coming from other than knowing it was somewhere along the top of the window frame. That is why I made multiple passes along the entire top of the window frame. This is why this thin runny silicone seems to be the solution.

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[Pacfanweb]

The Kent sealer specified by the TSB is great stuff.   I've done about a dozen of these so far, only one has come back. 

The Permatex flowable silicone will probably work....but you'll have the glass company cussing if you need the rear glass replaced.  They hate silicone.   That's why I don't use it for this, although I've been tempted. 

The updated TSB (as of about October, iirc) suggests either the Kent High Tech Clear or another product...which I cannot remember the name of at the moment.  Going to find that TSB and buy some of it and see if it's anymore flowable than the Kent.  Always looking for a better product, as I use this stuff daily. 

If the Kent was just a little bit more flowable, you could probably squirt it through the gap between the cab spoiler and the top of the glass, but...it's not.  It's advertised as "flowable", but it's more "self leveling" than actually flow.  Looks great when it's done, though.   I lay the bead, then smooth it with a glove on my hand, and it looks really good. 

 

This job takes me about an hour.  Not too much of a pain, but you have to be careful in a few spots. 

I have gotten to where I don't try to seal the ones that have multiple cracks already.  I just tell the dealership to replace the glass on those.  That seems like the proper way for them, to me.  

 

[Pacfanweb]

5 hours ago, 2016 Sierra Owner said:

GM is not going to come up with any other solution. Their fix is the TSB to seal the top of the window. If that does not work. The next step is to replace the whole window unit. I just had that done on mine. If it needs to go for a 3rd repair then it's time for me to file a lemon law case. The glass guy told me he did one a few days before where the guy didn't catch the leak in time and when he went to replace the window and removed the back seat. There was an inch of water in his floor board and the truck smelled like mold. I'd get it documented at the dealer that it leaks as soon as I could.

 

There's not really anything else they can do.  It's either seal the top of the glass, or replace it.   Other than actually updating the glass with an improved version, that's the only 2 options they have.   And if they do make a new glass, the ones out in the field still have to be fixed eventually. 

The sealing the top of the glass works most of the time, and looking at it from their side:  It costs them roughly a grand to replace one of these glasses.   The sealing costs probably 300, max.   If that only works half the time, (and it should be a lot more than that) it's saving them a ton of money.   

FYI, the F-150 has a similar problem with a plastic frame on the glass cracking and leaking. It's not identical to the GM glass, but the concept is similar and they have lots of leaks, too.   There's no option to seal them, though.  It's a new glass every time.   

[Pacfanweb]

On 3/6/2021 at 9:59 AM, MG386 said:

Yea, at this point I'd rather deal with a few drips. They're not touching the headliner(yet). And I really don't want dirty mechanic fingerprints all over my pillars and liner.

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Your mileage may vary with that.   You can't tell I've been there when I do one, other than it doesn't leak anymore.  But yeah, with a random dealership tech, that's a possibility, yes. 

[Pacfanweb]

On 3/3/2021 at 7:43 PM, RyanbabZ71 said:

There is another type of self leveling 3m adhesive I believe that is called out in the TSB


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Don't think it's 3M.   They suggest Kent Hi Tech Clear, and one other....I'd never heard of that company before I saw the TSB.  Looked them up briefly and you had to register to see anything, and I never did.  I'll look it up again and see how much that other product is.  Interested in seeing if it's any more "flowable" than the Kent, which I wouldn't really say "flows" so much as it kind of "self levels a bit".   Is a very good sealer, though.  

[Pacfanweb]

On 2/23/2021 at 7:25 PM, OnTheReel said:

So the point of jamming the rope seal into the spoiler is to keep water from running under the spoiler and into the cracked window channel? Seems like a band-aid at best.

 

I know I’m a broken record here, but all data suggests the spoiler itself is rarely, if ever, the sole cause of the leak. Trucks with solid rear windows have the same exact spoiler. And yet to my recollection in 200+ pages I have never seen a solid window truck posted here with a leak.
 

My hope is that the are redesigning what’s under the spoiler and therefore had to redesign the spoiler too.

Never seen a spoiler leak.  There are plenty of places where parts of it penetrate the cab...but never seen them leak.  Whenever I have one off, I seal all of them:  8 studs attached to the spoiler that stick through the cab.  4 holes on the ends that bolts from the inside screw into the spoiler.  The wiring grommet.  Another blank grommet on the right, same size as the wiring.  2 smaller holes that I've never seen with anything but a plug/grommet in them.  And 2 plastic "centering" clips.   
All those points with a hole in the cab for each of them.    Yet I've yet to see any of those leak.   Don't take chances when I have one off, though.   I seal them all, including removing all those grommets and sealing them, too. 

 

[RyanbabZ71]

Don't think it's 3M.   They suggest Kent Hi Tech Clear, and one other....I'd never heard of that company before I saw the TSB.  Looked them up briefly and you had to register to see anything, and I never did.  I'll look it up again and see how much that other product is.  Interested in seeing if it's any more "flowable" than the Kent, which I wouldn't really say "flows" so much as it kind of "self levels a bit".   Is a very good sealer, though.  

Here is what I was thinking of. This is not in the TSB




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[2016 Sierra Owner]

5 hours ago, Pacfanweb said:

There's not really anything else they can do.  It's either seal the top of the glass, or replace it.   Other than actually updating the glass with an improved version, that's the only 2 options they have.   And if they do make a new glass, the ones out in the field still have to be fixed eventually. 

The sealing the top of the glass works most of the time, and looking at it from their side:  It costs them roughly a grand to replace one of these glasses.   The sealing costs probably 300, max.   If that only works half the time, (and it should be a lot more than that) it's saving them a ton of money.   

FYI, the F-150 has a similar problem with a plastic frame on the glass cracking and leaking. It's not identical to the GM glass, but the concept is similar and they have lots of leaks, too.   There's no option to seal them, though.  It's a new glass every time.   

I'm not the one that said I was going to wait till GM comes up with something better till I get my window fixed. I was just replying to the guy that was waiting. My dealer used the TSB stuff to seal my window. It didn't work so I got a new updated replacement the other day. The TSB stuff my dealer used was actually still wet under the top dry layer. It's been on over a month. I could not believe it was still wet and not cured yet. Like I said the TSB was step 1 the new window was step 2 so if it leaks again it's lemon law time. It's only gotta make it 2 more years and it will be someone else leaker.

[Pacfanweb]

4 hours ago, RyanbabZ71 said:

 

Here is what I was thinking of. This is not in the TSB




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Don't believe I would use that. I have thought about it, though.

It certainly flows.  

Edit: the more I think about it, I don't reckon it would hurt. Kind of an expensive option, but if it works, it works. I would love to see if somebody used it, what the finished product looked like.

Don't know how much is in those, it might take two of those kits to do the whole thing. That's a pretty big gap to fill.

 

First one I did, I used just a squeeze tube of the Kent sealer. Took the whole tube. And it was a huge pain to squeeze out of there. I started buying them in caulking tubes after that. That's much easier

Edited March 8, 2021 by Pacfanweb