DIY sliding window leak permanent repair

GN2018 · February 7, 2022

I’m so thankful to Leevon for posting this. My original plan if I got a leak was to get the solid window. Now I’m thinking I’ll find someone to do the repair properly as shown in this thread. And, if I ever have the headliner or spoiler off for any other repair, I will make sure this is done. So sad that it’s not done this well in the factory, especially since it’s a know issue.

Thanks to the forum admin for pinning it.

Edited February 7, 2022 by GN2018

luke1333 · February 8, 2022

@Leevon thanks for the post! My truck started leaking last week and finally got around to doing it today. Perk of working in dealer is I could help do it so I also added strip caulk around all the bolts. Used the seam sealer GM recommended in the bulletin. My spoiler only had one seal on the 12 holes as well! Thanks again for all the tips! I thought about the camera/mirror upgrade as well but not wanting to spend $800+ right now! But now I know it isn't terrible to do!

Leevon · February 21, 2022

On 2/8/2022 at 12:38 PM, luke1333 said:

@Leevon thanks for the post! My truck started leaking last week and finally got around to doing it today. Perk of working in dealer is I could help do it so I also added strip caulk around all the bolts. Used the seam sealer GM recommended in the bulletin. My spoiler only had one seal on the 12 holes as well! Thanks again for all the tips! I thought about the camera/mirror upgrade as well but not wanting to spend $800+ right now! But now I know it isn't terrible to do!

Glad you got to put hands on it! I think they're entirely 100% fixable and it's frustrating that the bulletins, and dealer practices don't line up.

luke1333 · February 21, 2022

55 minutes ago, Leevon said:

Glad you got to put hands on it! I think they're entirely 100% fixable and it's frustrating that the bulletins, and dealer practices don't line up.

Yeah mine was pouring after almost 2 years of ordering it, just started out of the blue. Resealed it all up, bolts etc etc and started to barely leak again. Going to put window in and camera mirror I guess this time around!

Pacfanweb · March 8, 2022

On 1/17/2022 at 1:56 PM, newdude said:

I hope you got new nuts before you put it all back together.

They're only considered not reusable because they come with sealer on the washers, and it is basically destroyed when you remove them. If you just put some sealer on them when you reinstall, you can reuse them just fine.

hihosilverado · April 3, 2022

How flowable is the seam sealer? Could this be done without removing the spoiler and just masking well and running the bead through the gap between the spoiler and top of glass? I noticed that 3M makes a clear flowable self leveling seam sealer…

Leevon · April 5, 2022

On 4/3/2022 at 1:26 PM, hihosilverado said:

How flowable is the seam sealer? Could this be done without removing the spoiler and just masking well and running the bead through the gap between the spoiler and top of glass? I noticed that 3M makes a clear flowable self leveling seam sealer…

It's self-leveling which means it does have some flowability. I think you might have success but it'd be a gamble...would be curious to see it tried.

AJMBLAZER · April 6, 2022

Yes you can do it without taking the spoiler off. Just did it last week.

Absolutely pouring rain now. We’ll see how it does.

hihosilverado · April 6, 2022

6 hours ago, AJMBLAZER said:

Yes you can do it without taking the spoiler off. Just did it last week.

Absolutely pouring rain now. We’ll see how it does.

How did it do?? Which sealer did you use?

AJMBLAZER · April 6, 2022

Well, so far so good. Drove through absolutely pouring rain for 45 minutes on the highway this morning and then sat in the parking lot for 6 hours under rain ranging from a steady rain to a pouring downpour. I can't see a sign of a leak now.

I used the Permatex sealant mentioned in another thread. Worked great. Might still go get a 3rd tube and put more on the window's top edge because I was a bit shocked at how much just sort of disappeared out of sight after I put it in there. GM sure didn't use a lot of it's sealant and they definitely left a lot of void space for the water to sit. Now I can see the sealant all the way across if I put my face up next to the spoiler and look down into the space between the glass and the cab.

WeGone · April 7, 2022

15 hours ago, AJMBLAZER said:

Well, so far so good. Drove through absolutely pouring rain for 45 minutes on the highway this morning and then sat in the parking lot for 6 hours under rain ranging from a steady rain to a pouring downpour. I can't see a sign of a leak now.

I used the Permatex sealant mentioned in another thread. Worked great. Might still go get a 3rd tube and put more on the window's top edge because I was a bit shocked at how much just sort of disappeared out of sight after I put it in there. GM sure didn't use a lot of it's sealant and they definitely left a lot of void space for the water to sit. Now I can see the sealant all the way across if I put my face up next to the spoiler and look down into the space between the glass and the cab.

Does your rear window still work?

AJMBLAZER · April 7, 2022

@WeGoneYes. Over the sliding window the new sealant is just going between the track frame and the body.

hihosilverado · April 13, 2022

On 4/6/2022 at 6:31 AM, AJMBLAZER said:

Yes you can do it without taking the spoiler off. Just did it last week.

Absolutely pouring rain now. We’ll see how it does.

I ended up ordering the Kent clear seam sealer in the TSB and doing it yesterday. I masked both sides of “the gap” and taped a sheet of plastic into the bed to catch drips. I did soak the tube of seam sealer in hot water for a bit so it would flow better.

It rained like crazy today for several hours and no signs of any leak. My truck is an early build 2021 and I had a tiny leak start around 14k miles.

Pacfanweb · July 3, 2022

On 4/3/2022 at 2:26 PM, hihosilverado said:

How flowable is the seam sealer? Could this be done without removing the spoiler and just masking well and running the bead through the gap between the spoiler and top of glass? I noticed that 3M makes a clear flowable self leveling seam sealer…

It flows pretty well.
The Kent Automotive Hi-Tech Clear that's in the GM bulletin also "self levels" a bit...it's not as runny as the 2 part seam sealer in this thread, but does a good job as well.
It's true about the nuts not needing to be replaced. Only reason they recommend it is because they have a sealant on them and it's basically destroyed when you tighten them...but it's INSIDE the cab, which isn't the ideal place for sealer to begin with.
You want to seal the outside if you have the choice, which you do when you remove the spoiler.

I cut, form and use 3M Ribbon Sealer on the outside, around all the holes. It's butyl, and will last longer than you'll live. There are other products that will work as well, but I use that frequently and always have it, and it's fantastic for the job.

The key here is to make sure all the surfaces the sealer is going to touch are clean, clean, clean. Especially that inside of the glass itself. If the sealer doesn't adhere to the glass and it pulls away, you can have the leak again.

Pacfanweb · July 3, 2022

On 4/12/2022 at 9:43 PM, hihosilverado said:

I ended up ordering the Kent clear seam sealer in the TSB and doing it yesterday. I masked both sides of “the gap” and taped a sheet of plastic into the bed to catch drips. I did soak the tube of seam sealer in hot water for a bit so it would flow better.

It rained like crazy today for several hours and no signs of any leak. My truck is an early build 2021 and I had a tiny leak start around 14k miles.

Yes, if it's warm weather the Kent flows better. If it's winter and I need it to flow more, I just start my truck, set it under the vent and blast the heater for a few minutes, and that does the trick.

That works for most all sealers, btw. I once saw a glass company on a lot that fabbed up a box that they stood sealer tubes in, and the ran lines from the engine coolant to it and literally had coolant pumping through the void outside the box, to keep their tubes of urethane warm so it flowed better. Worked, too. Flowed like butter.