2025 Chevrolet Traverse

On September 30 I was on my way to work as I was merging to join a busy highway my breaks failed to work. I had to press them really hard but it took for ever to yield. I made hand signals to the cars I was about to strike and they were able to break before I hit them as I was merging. When this happened 3 service lights appeared. Service ESC system, Break assist failure. Press hard to break.Speed limited. Key missing, check for key. i had an appointment for a cracked windshield on Friday the 3rd and Richland Chevrolet in Roswell. I took my traverse in on Wednesday afternoon and never heard back from them. on Monday October 6 I called and they advised me that my car needed a master cylinder and it was on back order. They said they could not give me an ETA because they have no idea when it will be available. They do not have a loaner because I did not purchase the vehicle their so I called the dealership where I bought it and they cant help me either.

my wife was driving and she got warning lights for "brake assist failure" "speed limited" and "Service ESC". Brake pedal went all the way to floor and she came to a rolling stop. She couldve been in a accident if there were vehicles in front of her and it was also near a school bus stop. We recieved the vehicle from the shop a week ago today for other issues. (onstar). Was also in shop at dealership prior to that for coolant leak, a/c failure and a loud humming noise. Also door latch to rear hatch.

Started 09/17/25: While braking, a front-end clunk or thud occurs. Directly afterwards, a cluster of warning lights appeared including Brake, ABS, Collision avoidance/forward collision, and Stabile track stability control) Brake pedal is now inconsistent and soft. Every time the brakes are activated, the thud or clunk occurs. When I start the vehicle, I get warning messages of Service Brake Assist, Service ESC on the dash that I must acknowledge. Called Hendricks Chevy Columbia SC on 9/18/25. Told to bring into dealership on 9/19/25. Dealership attempted diagnosis but could not. They bled brakes and reset all warning lights. I drove car approx. 10 miles and symptoms reoccurred, including all warning lights and thud/clunk. Called Dealership again and told to bring into on 9/22/25. It is now 9/23/25 and they have not diagnosed it yet. I was assigned a loaner car for 5 days.

- Brake assist system failure -Electronic stability control alert - Brake pedal goes to the floor and car doesn't stop -Potential master cylinder malfunction due to faulty part. (See photo below). Safety of self and others put at risk as car became uncontrollable due to complete loss of braking power while driving. Dealership has not notified yet due to long waiting of other vehicles undergoing maintenance (in my case 2 days at time of this report) Part hasn’t been inspected yet. Issue seems in line with similar incident referring to other 2025 and 2024 Traverse molels. Warning signs and alerts appeared only at time of incident (See photo below)