Rear window leak

DHBWA · April 27, 2025

The repair on my two 2019’s is still holding after two years of living outside. I did the permanent fix by removing spoiler and completely sealing the top of the slider.

EXSlider400 · April 27, 2025

3 hours ago, GN2018 said:

I would look at the “DIY sliding window leak permanent repair.” post in this forum. It’s a sticky. I don’t see myself as capable of doing that repair, but if my Denali starts to leak, I’m going to find someone to do that repair as I believe it is the best way to ensure that the leak is fixed properly and gives the best chance at it being for good.

I had to do the epoxy repair mentioned above after 2 dealer attempts. The plastic frame is a design flaw so replacing it with the same thing is just delaying the leak (and when I removed the rear seat, one of the cab vents was popped out so huge opening for water to get through). But after the fix mentioned here it has been a few years (including a 10k mile 3-week trip on the Dempster Hwy which is extremely rough) and no leaks. But I also put sealant around every bolt and washer both sides of the mounting holes (so inside and outside).

Edited April 27, 2025 by EXSlider400

Josh_166 · April 28, 2025

I may have to remove the rear spoiler. It's still leaking in but not nearly as bad. So guess I'll cut all the silicone out and pull the headliner out then the spoiler and seal it all. Either that or I clean it up and trade the truck off.

DHBWA · April 28, 2025

I’m sure you know but you only have to pull the headliner down enough to remove the spoiler nuts. It’s really not that bad. Even if you crease the headliner it’ll straighten out after a day or two…

EXSlider400 · June 23, 2025

Is this still an issue with 2025 trucks? I assume so and if that is the case then I will have to do the fix in the future for my new 2500 (traded in the 2019 1500).

Z06JPB · June 23, 2025

2 hours ago, EXSlider400 said:

Is this still an issue with 2025 trucks? I assume so and if that is the case then I will have to do the fix in the future for my new 2500 (traded in the 2019 1500).

As of March 2023, the TSB 18-NA-383 only covers a repair procedure for 2019-2020 models. The only authorized repair for 2021+ model years is to replace the entire rear window which in my opinion is the better way to fix this issue anyway.

outrag1 · June 23, 2025

It looks like there may be a re-design for the new 2027 model. The frame around the slider is different. Not sure about the roof spoiler or any other potential leaking spots...

2027 Chevy Silverado To Feature New Rear Window: Photos

Edited June 23, 2025 by outrag1

mandrewbot3k · October 5, 2025

On 6/23/2025 at 7:00 AM, Z06JPB said:

As of March 2023, the TSB 18-NA-383 only covers a repair procedure for 2019-2020 models. The only authorized repair for 2021+ model years is to replace the entire rear window which in my opinion is the better way to fix this issue anyway.

24-NA-103 covers 2022-2024 for the same 'fix'.

Oddly it seems 2021 was skipped, so they may not have shipped a lot of trucks with the rear slider due to covid?

mandrewbot3k · October 5, 2025

On 6/23/2025 at 7:20 AM, outrag1 said:

It looks like there may be a re-design for the new 2027 model. The frame around the slider is different. Not sure about the roof spoiler or any other potential leaking spots...

2027 Chevy Silverado To Feature New Rear Window: Photos

Will this be a drop-in replacement or the 2027 too much of an overhaul?

Rocko · July 22

Wish I would have came here sooner! 2019 trail boss bought with roughly 14,000 miles. Not long after owning it I smell mildew and started investigating. Water had been leaking into the rear window somewhere. The rear headliner was water stained in the whole backseat area. Took it in to my dealer atleast 4 times for this. headliner replaced and rear window along the way. I now have around 84,000 and just the other day noticed a mildew smell again and sure enough the headliner is water stained again. Its currently at the dealer so I cant see what the build date is right now. I'm just hoping they cover they're work performed in the early stages of this now that I'm out of warranty!!! I'm supposed to get an update later today or tomorrow. My dealer has been great to work with but I think I need to get GM involved as this is unacceptable!!