by Lawsuit against GM over rear window leaks in pickup trucks
Trucks are supposed to be tough. They must withstand the harshest conditions, battle the elements, and be off-road capable. However, according to several GMC and Chevrolet owners, their pickups cannot even handle rain without leaking water into the cabin.
A new class-action lawsuit in California alleges that the rear sliding windows installed in some Chevrolet and GMC pickups leak water into the cabin, which can damage electronics, interior trim, and create conditions for mold growth. More importantly, the lawsuit claims that GM knew about the defect long before many owners discovered it on their own.
An unexpected $1,000 bill for one owner
The lawsuit, filed by California resident Filiberto Loza Gonzalez, covers certain 2019 and 2020 model year Chevrolet Silverado and GMC Sierra trucks equipped with power sliding rear windows. According to the lawsuit, Gonzalez discovered a water leak in his 2019 GMC Sierra 1500 while washing the truck. Although the dealer allegedly confirmed the problem and performed a repair, the owner claims he was billed over $1,000.
Gonzalez appears not to be the only one facing this issue. Forum and social media users report similar incidents. One user on GM-Trucks.com writes:
GM will try to patch the cracks in the windows with sealant instead of replacing the defective window. Many people on the forums report that the sealant does not hold up long, as was the case with mine. If you are unlucky and the warranty has already expired when the sealant fails, GM will not cover anything without a fight.
A bulletin that GM kept revising
Over the years, GM appears to have been aware of the issue and continuously updated a technical service bulletin in an attempt to resolve it. This effort now seems to be a key piece of evidence in the case. According to Technical Service Bulletin 18-NA-383, technicians were instructed to inspect for cracks in the upper plastic guide of the rear sliding window — a condition that could allow water to bypass the urethane seal and enter the vehicle.
GM’s prescribed repair involved removing the rear roof spoiler and applying a seam sealer along the top of the window assembly. The document also notes that if the repair failed and the vehicle returned with the same issue, dealers were supposed to replace the entire rear sliding window assembly.
This last detail may prove significant. The lawsuit alleges that GM concealed the defect related to the use of substandard materials and continued to sell affected trucks knowing about the problem. The fact that the bulletin underwent numerous revisions over the years could be a point of contention. The version from March 2023, included in the court documents, is labeled as version 13 and shows a revision history dating back to the bulletin’s initial release in early 2019.
The proposed class includes owners and lessees in California of certain 2019 and 2020 model year Silverado and Sierra 1500, 2500HD, and 3500HD trucks. At this time, the allegations remain unproven, and GM has not been found liable. Nevertheless, many affected owners should closely monitor further developments.
This lawsuit could set a precedent for other owners who have faced similar problems. If the court finds GM guilty of concealing the defect, it could lead to widespread compensation payments and a mandatory recall of vehicles for free repairs. Additionally, this case highlights the importance of technical bulletins as evidence in lawsuits against automakers, as they often demonstrate the company’s awareness of a problem long before it becomes widespread. Owners of 2019-2020 Chevrolet and GMC pickups should check their vehicles for leaks and contact their dealer, even if the warranty has already expired.
