While driving my truck approximately 45 mph on a street, I heard the vehicle notification alarm sound, I looked down at the dash and had several warning lights illuminated:I had four messages: Service ESC service trailer brake brake system failure - 62 mph top speed steering assist reduced drive with care lights on dash that were illuminated ABS check engine brake traction control before I could read each warning light, a red stop light was approaching. I was at that time I pressed on the brakes and realized that my brakes were extremely spongey. I figured I only had about 10% braking power. With my two year old in the back seat, I pushed as hard as I could to stop my truck. Luckily, by the grace of god, I was able to stop my truck without rear ending the car in front of me. My truck was then towed to the dealership. I bought the truck 5 days prior. My truck has approximately 161 miles on it. The dealer told me the next day I needed a new master cylinder and hydro boost. Probably the absolute worse component to fail on the driver while the vehicle is in motion.

- La Habra, CA, USA

Rear wheel brakes unexpectedly lock up after driving over a hour or more

- Brooklyn, NY, USA

Have about 6000 miles on my 2019 GMC seirra denali 5.3. I've been experiencing a very troubling issue been to the dealership once already and had a hard time convincing them that something was wrong with the truck.every time I drive for long periods of time or idle for 10+ mins when I shift from park to drive I cannot go faster than 5 mph without the rear brakes locking up. I do not know if this is some kind of limp mode or what.

- Brooklyn, NY, USA