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General Motors is facing a proposed class action lawsuit alleging that several Chevrolet, GMC and Buick vehicles can develop coolant leaks because of defective radiator hose connectors. The complaint claims the problem can occur relatively early in a vehicle’s life and may lead to engine damage and unexpected repair costs.
What is the problem?
The lawsuit covers 2023-2026 Chevrolet Colorado and GMC Canyon trucks equipped with the L3B 2.7-liter turbocharged four-cylinder engine. It also includes 2024-2026 Chevrolet Traverse, 2024-2026 GMC Acadia, and 2025-2026 Buick Enclave models fitted with the LK0 2.5-liter turbocharged four-cylinder engine.
According to the complaint, the vehicles use sealed cooling systems designed to circulate coolant between the engine and radiator. However, the lawsuit alleges that the quick-connect fittings on the radiator hoses can fail prematurely, allowing coolant to escape, causing the engine to run without sufficient fluid to regulate its temperature. If the problem is not detected quickly, the lawsuit claims it can result in overheating and potentially serious engine damage.
The case was brought by a Georgia owner of a 2024 Chevrolet Colorado who says his check engine light came on at around 44,400 miles. A dealership reportedly diagnosed a coolant leak from the upper radiator hose connector and identified a P3075 trouble code. The owner says he was charged $489.36 for the repair.
The lawsuit also points to a GM service bulletin issued in March 2026 concerning upper radiator hose connector seal failures on Colorado and Canyon trucks. The plaintiff alleges that GM’s coverage did not extend to his vehicle because it was beyond the three-year/36,000-mile bumper-to-bumper warranty.
What owners should do
Owners of the affected models should watch for warning lights, low coolant levels, unusual engine noises or signs of overheating. Anyone experiencing these symptoms should arrange an inspection with a GM dealership.
Keep copies of repair invoices, diagnostic reports and communications with GM, especially if a coolant leak has already resulted in an expensive repair or the problem has returned.
How GM owners can take back control
A cooling-system problem can become much more expensive if a small leak develops into engine damage. Owners who have already paid for repairs or are facing recurring coolant problems may want to understand whether they have options beyond simply covering another repair bill.
The Lemon Firm can review your vehicle’s repair history and help determine whether your circumstances may support a legal claim. If you’ve experienced a persistent defect with your Chevrolet, GMC, or Buick, contact us today to speak with a case analyst and better understand your rights.