GMC Sierra Owner Hits GM With Lawsuit Over Leaky Rear Window

A California man is taking General Motors to court after a leaky rear window cost him more than $1,000 in repairs. The proposed class-action lawsuit, filed by Filiberto Loza Gonzalez, targets certain 2019 and 2020 Chevrolet Silverado and GMC Sierra trucks equipped with power-sliding rear windows.

Gonzalez says water leaked into the cabin of his 2019 GMC Sierra 1500 while he was washing it, soaking interior components and potentially creating a mold risk. A dealership confirmed the problem and fixed it, but Gonzalez alleges GM left him holding a four-figure bill.

The lawsuit argues GM knew about the defect for years but kept it quiet. Online forums are filled with similar stories from owners who say dealerships tried quick fixes like sealant instead of replacing the window. com wrote that the sealant didn't hold, and once the warranty expired, GM refused to cover further repairs without a fight.

The complaint centers on a technical service bulletin, labeled 18-NA-383, that GM updated at least 13 times since its 2019 release. The bulletin instructs technicians to check for cracks in the window's plastic upper rail guide, which can let water bypass the seal.

GM's prescribed repair involves removing the rear spoiler and applying seam sealer. If the fix fails, the bulletin says dealers should replace the entire window assembly. The lawsuit claims GM concealed the issue by using substandard materials and kept selling affected trucks anyway.

The proposed class covers California owners and lessees of 2019 and 2020 Silverado and Sierra 1500, 2500HD, and 3500HD models. For now, the allegations are unproven, and GM has not been found liable. But for anyone dealing with a wet cab, this case is worth watching closely.