GM Lawsuit Says Silverado And Sierra Trucks Can Leak Water Into The Cabin

General Motors is facing yet another class action lawsuit, alleging that faulty rear sliding window seals in several Chevy and GMCpickup trucks allow water to leak into the cabin, potentially causing costly damage for owners. This is not the first GM pickup to suffer from a leaky rear window, either.

The complaint was filed in a California federal court and argues that the automaker knew about the issue before the affected vehicles were sold, yet failed to disclose it to customers.

Faulty Rear Window Design

According to the lawsuit, the problem affects certain 2019 and 2020 Chevrolet Silverado and GMC Sierra 1500, 2500 HD and 3500 HD models equipped with rear sliding windows. The plaintiff, Filiberto Loza Gonzalez, claims the plastic-framed rear window assembly can develop leaks around its seals, allowing water to enter the rear of the cabin. Besides causing inconvenience, the complaint alleges that prolonged water intrusion can damage electrical components and interior trim, and even encourage mould growth. The lawsuit stems from Gonzalez’s experience with his 2019 GMC Sierra 1500 after he reportedly discovered water entering the cabin while washing the vehicle.

Although a dealership confirmed the leak and carried out repairs, Gonzalez says he was left with a repair bill of more than $1,000. The lawsuit also warns that the consequences could extend well beyond a wet interior, stating: “Electrical failure can result in vehicles being unsafe to drive due to the failures of the electrical and mechanical systems, rendering them unfit for safe operation on the roadway.”

Technical Bulletin Under Scrutiny

A major focus of the complaint is GM’s Technical Service Bulletin 18-NA-383, which outlines repair procedures for water leaks around the rear sliding window. According to the filing, the bulletin has been revised numerous times over the years. The service bulletin’s existence suggests the issue has appeared on previous vehicles, lending weight to the plaintiff’s argument that this is far from the first time owners have experienced the leak. The lawsuit goes even further, claiming: “GM has willfully, knowingly and wrongfully failed to disclose the existence of the water intrusion defect to consumers.”

GM is also facing another class action lawsuit involving its 10-speed automatic transmission. On top of that, the company has recently had to recall more than 26,000 Chevrolet Express and GMC Savana vans over a steering gear defect. Despite these legal challenges, GM remains America’s best-selling automaker after delivering 714,896 vehicles in the United States during the second quarter of 2026.

Jury Trial Requested

The rear window lawsuit adds yet another legal challenge for the Detroit automaker, although it remains in its early stages. Gonzalez is seeking a jury trial and is asking the court to award declaratory relief along with exemplary, compensatory, and statutory damages on behalf of himself and all proposed class members. Whether the case ultimately results in compensation or no liability at all will be decided in court. For now, however, it adds another lawsuit to GM’s growing list of legal battles and places fresh attention on whether the company acted in good faith after becoming aware of the alleged defect.