— A General Motors brake master cylinder failure lawsuit alleges five popular 2025 models should have been recalled because of braking system problems.
But the vehicles have not been recalled over the master cylinders, and three GM owners complain the automaker knows the braking systems are defective.
The original class action was filed by two vehicle owners in October 2025, and GM responded by arguing the customers sued for more than $5 million after their master cylinders were replaced for free.
The original lawsuit also included New York and Pennsylvania only, but the modified and refiled master cylinder lawsuit adds the state of Missouri.
This refiled class action includes all persons or entities who purchased or leased a 2025 Chevrolet Traverse, 2025 GMC Acadia, 2025 Buick Enclave, 2025 Chevrolet Colorado, or 2025 GMC Canyon vehicle in Missouri, New York or Pennsylvania.
Pennsylvania plaintiff Eric Barron owns a 2025 Chevrolet Traverse equipped with a brake master cylinder that failed and was replaced for free by General Motors. But the plaintiff complains the loaner vehicle provided by GM was smaller than his Traverse.
He sued GM over "claims for violations of the Pennsylvania Lemon Law, breach of express warranty, breach of implied warranty of merchantability, fraudulent concealment, and unjust enrichment."
New York plaintiff Chelsey Thompson owns a 2025 Chevrolet Traverse equipped with a master cylinder that failed. The brake master cylinder was replaced by GM for free, but the plaintiff complains General Motors violated the New York Lemon Law and the express warranty.
She further asserts GM is guilty of "breach of express warranty, breach of implied warranty of merchantability, fraudulent concealment, and unjust enrichment."
Missouri plaintiff Simon Moeller owns a 2025 GMC Acadia equipped with a brake master cylinder that failed. Although GM replaced the component for free, the plaintiff sued over "claims for violations of breach of express warranty, breach of implied warranty of merchantability, fraudulent concealment, and unjust enrichment."
Once the brake master cylinder was replaced, each plaintiff wrote to General Motors and complained all the above model year 2025 vehicles are defective.
The plaintiffs contend GM knew the brake master cylinders were defective because of the "higher-than-expected number of replacement master brake cylinder assemblies ordered by GM dealerships." However, the owners don't say how many master cylinder replacements have occurred.
The class action lawsuit wasn't filed until after GM issued Service Update N242482170 to dealerships regarding brake master cylinder problems. The bulletin concerns master cylinder failures in 2024 Chevrolet Traverse and 2025 Buick Enclave vehicles.
"Certain vehicles listed above may have a condition in which the internal cartridge seal in the eBoost Module is missing. Dealers are to replace the brake master cylinder." — N242482170
General Motors argues none of the three plaintiffs own a 2024 Chevrolet Traverse or 2025 Buick Enclave, the vehicles named in Service Update N242482170. But the class action lawsuit argues the same braking system components are installed in the vehicles owned by the plaintiffs.
Additionally, the lawsuit asserts the same brake master cylinders are installed in the 2025 Chevrolet Traverse, 2025 GMC Acadia, 2025 Buick Enclave, 2025 Chevrolet Colorado and 2025 GMC Canyon.
According to the lawsuit, the seals inside the brake master cylinders fail prematurely which allows brake fluid to leak. This can cause a sudden loss of hydraulic pressure and braking performance.
According to the GM lawsuit, a master cylinder failure can activate a brake warning light, the ABS warning light and the “Service Brake System” message. The class action also alleges the brake pedal can feel hard or it may fall to the floorboard.
The GM brake master cylinder failure lawsuit was filed in the U.S. District Court for the Eastern District of Pennsylvania: Barron, et al., v. General Motors LLC.
The plaintiffs are represented by Sergei Lemberg.