Rear Window Leak and GM warranty warning

Danny Vee · August 20, 2024

I have a 2021, with only 31K miles and I have a leak. Date of purchase was April of 21 so I'm 4 month past the warranty date. This truck is still basically new and because it is four month past the warranty date they won't even look at it, but when I told them what the issue was they were well aware of the problem. Just said I had to go to a window shop. Com'on Chevy, you can do better then that.

Z714Mike · August 20, 2024

Agreed. I have a 2020 and had the same issue last year. Chevy said a faulty silicone job at the factory but would not take responsibility.

SOL I guess. Good luck.

mrjulian416 · September 10, 2024

My 2021 developed the leak at around 40k miles.

I ended up sealing it on my own using butyl rope on the fasteners and some 3m 08367 black urethane seam sealer in the channel, following the DIY thread on here. The job wasn't as bad I expected it to be, taking my time with dropping the rear half of the headliner and releasing the clips on the spoiler... didn't break anything.

Took my time cleaning the channel with soapy water, denatured alcohol, compressed air.

Two months and 2k miles later (and plenty of rain) so far so good. I guess if it starts leaking again I'll go with a fixed window.

Hard to believe they haven't solved this problem.

PESandoval · November 19, 2024

I have a 2020 GMC Sierra SLT Crew cab its out of warranty and the back window is leaking on both sides of the window

Fernando martinez 17 · December 28, 2024

I just noticed a leak in the rear window area of my 2020 gmc 1500 Denali. The weird this is that the headliner is wet as if the water is coming in the top of the cab

mrjulian416 · December 28, 2024

3 hours ago, Fernando martinez 17 said:

I just noticed a leak in the rear window area of my 2020 gmc 1500 Denali. The weird this is that the headliner is wet as if the water is coming in the top of the cab

Could be one of the spoiler mounting bolts leaking. It's all just a $hitty design all around.

amyredchevy · January 5, 2025

2019 gmc sierra 2500hd. Just discovered my back window was leaking. Went to get in my truck and squish. The whole floor board is saturated. I'm just outside my warranty so who can I contact to have it fixed.

mrjulian416 · January 6, 2025

Out of warranty you're best bet is to either seal it yourself or take it to any automotive glass shop (not the dealer).

amyredchevy · January 8, 2025

Found where the leak is coming from. The cabin pressure relief vent below the rear window on the drivers side. Ordered a new one. Will be here tomorrow. Now just to see how to change it out.

shadow gray 2020 hd · January 23, 2025

Mine was repaired at the dealership with sealant a couple years ago. I am not digging up the old thread I posted to before. Mine hasn't started leaking again yet. I would definitely be interested in a class action lawsuit though in the event it does.

Kate and Mike · June 4, 2025

So I was told by a GM rep that they would fix the seal in my rear window (3rd light assembly). Now I'm being told they won't because it's out of warranty. They will do a cost assistance claim, which I was told by the supervisor at GM customer service wouldn't be worth it that I might as well use my extended warranty. My platinum warranty 5yr/100,000 originally told me they would cover it and now they wont cover it either because its concidered a leak. The dealership isnow telling me instead of sealing it the need to replace the window. What is everyone doing about this? My understanding is that this is a known issue for GMC and Chevy 2019-2023 models and that theirs a bulletin about this with the dealerships. How do I make GM pay for this since I didn't even know it was happening and it's been getting wet behind my leather seats all the way under it and my headliner is now stained. I would think this is causing a health issue with mold or mildew and a fire hazard since I have the electric back window and the defrost. Grateful for any response or suggestions. I'm willing to contact whomever to get this resolved. Ive even though about contacting an attorney on the matter. Thanks.