2021 Chevrolet Blazer brakes problems

Filed Sep 30, 2026 · Brakes · 120,000 miles · GA

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed and making a turn, the vehicle lost braking functionality. The brake pedal was depressed to the floorboard. After exiting the vehicle, the contact became aware of a fluid leak underneath the vehicle. The "BRAKE Failure" warning light was illuminated. The manufacturer was notified of the failure. The vehicle was taken to a local dealer, where technicians diagnosed a fluid leak from the vacuum pump, causing the brake failure. The contact referenced the federal safety agency Campaign Number: 19V645000 (Service Brakes, Hydraulic) as a possible cause for the failure. However, the VIN was not included in the recall. The dealer replaced the vacuum pump, and the vehicle was repaired. The failure mileage was 120,000.

Filed Sep 17, 2026 · Brakes, Engine · WI

Vehicle Information: 2021 Chevrolet Blazer 2.5L engine, VIN [XXX]. Odometer 118000 miles.Description of Incident: While operating the vehicle, the mechanical brake vacuum pump experienced a catastrophic internal failure. The drive gear housing shattered violently without warning, shearing off the end of the connecting engine camshaft. Because this was an instantaneous mechanical failure, the vehicles computer did not trigger any dashboard warning lights, check engine lights, or safe mode protocols prior to the failure.Safety Hazards and Component Damage: First, the total destruction of the vacuum pump caused an immediate compromise to the brake booster vacuum lines, resulting in a sudden, dangerous loss of power braking assistance. Second, the sheared camshaft breached the engine valve cover or head, causing the engines pressurized oil system to instantly dump all engine oil externally onto the ground. Third, shrapnel or violent structural torque from the instant engine seizure punctured or severed the adjacent transmission cooler fluid lines and compromised brake fluid lines, causing total loss of transmission fluid and brake fluid simultaneously.Request for Action: This failure mirrors the exact mechanical defects documented in GM Technical Service Bulletin 21-NA-268 and previous GM vacuum pump recalls like the federal safety agency Recall 19V‑645, which excluded the 2021 Blazer. I am filing this report because the lack of an electronic warning indicator before a catastrophic mechanical brake and engine failure poses an extreme, immediate threat to highway safety. GM must expand recall coverage or issue a Special Coverage Adjustment for this model year. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 29, 2026 · Brakes, Engine · ID

Went to park car in a park to drop daughter off and it sputtered out and stalled out of nowhere with no warning. I had received a lamp warning very sporadically prior to this and on occasion that stated 'reduced steering assist drive with care' this resulted in heavy steering for that drive until car was shut off and then it would go away and be fine again, fixed the car through Knudtsen Chevy due to a recall about a month before on the issue with the engine being turned off and it thinking it was still hot and still running the fan (even though the car was not running). Knudtsen fixed that issue. Low battery voltage light did not come on however battery was older so had battery installed at park to ensure the issue was not due to the battery. The oil was fresh and showed no issues, changed 2 weeks before fresh oil no issues found during service. When tried to restart the car it would think it would try to start and then sputter out and not stay in idle. Les Schwab left and called a mobile mechanic to bring the computer. Computer was hooked up and it would try to start, however, it would not know it was already running and try to start again on it's own...the codes that came up were the PO101 code came up for Mass Air Flow issue...and then the codes would go in a wild sequence of fail.....mechanic checked for loose connections around air filter, took air filter out and it was clean no issues, checked pipe no visible issues. We walked away and walked around the park to give it some time to sit and then we tried it again and it tried and sputtered out and died again would not stay idling. Then all of a sudden we heard it try to start itself without us trying to start it and it clanked. We hauled it to Knudtsen for a diagnosis. They stated "the motor will not turn this way or that way and it is seized or locked up". This is a 2021 with only 89,000 miles it should have a longer life than this. Please investigate and is there anything we can do to fix it?

Filed Apr 22, 2026 · Brakes · 31,000 miles · IN

The contact owns a 2021 Chevrolet Blazer. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the vehicle with several unknown warning lights illuminated. The contact stated that the electronic parking brake independently activated. Additionally, the failure had occurred while the vehicle was parked. The failure was persistent. The vehicle was not diagnosed or repaired by an independent mechanic or a dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 31,000.

Filed Sep 20, 2025 · Brakes · GA

Brake booster failed after 50k miles needing repair. Brake became very still, prolonging the time it takes to stop the vehicle

Filed Jul 30, 2025 · Brakes · CA

My name is [XXX] and I was a passenger in our 2021 Chevy Blazer with our young child in the back seat when the brakes suddenly failed while we were driving on the freeway. The brake pedal went stiff and wouldn’t respond. It was terrifying — we truly felt like we were going to crash. I was panicked, and my child was crying. Since then, I’ve been too afraid to drive or ride in this vehicle, even if it gets repaired. This isn’t the first issue with the car, and GM has not resolved it in a timely or helpful way. The vehicle is currently at the dealership and we are paying for a rental car out of pocket. I’m reporting this because I believe this vehicle poses a serious safety risk to families like mine. I’m asking the federal safety agency to please investigate this issue before someone gets hurt. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 28, 2025 · Brakes · CA

While driving my 2021 Chevrolet Blazer LT on the freeway with my wife and child, the “Brake Assist” warning came on and the brake pedal suddenly became extremely stiff. I was going about 65 mph, and it became difficult to slow down safely. We were terrified. This created a serious safety hazard, as I almost couldn’t stop in time and could have caused a crash or gotten someone killed. The check engine light came on as well. I had previously taken the vehicle in for a similar rattling or braking noise back in 2021 and was told it was “fine.” Now the issue seems to have gotten worse. I have since learned that other owners have reported similar brake assist issues on 2021 Chevrolet Blazers, and it appears there are service bulletins but no recall yet. I am extremely concerned that GM has not addressed this defect, especially since it happened without warning and endangered my family’s lives. I am requesting a full investigation into this issue and for GM to take full responsibility for the repair.

Filed Jul 24, 2025 · Brakes, Driver assistance · TN

Brakes bottomed out. Message on my dash board said “Brake System Failure reduce speed to 62” and the brake went on the way to the floor.

Filed Jun 29, 2025 · Brakes · LA

My 2021 Chevrolet Blazer experienced brake failure while driving, without any warning lights or diagnostic alerts from the vehicle’s onboard system prior to. This created a very dangerous situation for myself and others on the road, including my family who was in the car as well. Prior to this incident, I brought the vehicle to the dealership not long after purchasing it because I was constantly hearing screeching noises when braking. I thought it was rather soon to need new brakes, considering I purchased the vehicle brand new, but the issue was dismissed without any further inspection. This most definitely resulted in a missed opportunity to diagnose what is seemingly a more well known mechanical failure common among GM manufactured parts. After the brake failure, service technicians discovered that the vacuum pump had failed, causing the brakes to fail which led to engine damage by projecting shrapnel into the engine. This has rendered a $35,000 car purchase useless after 4 years of use without a $10,000 repair. I find this highly unethical. Upon further investigation, I learned that GM has previously acknowledged vacuum pump failures in several vehicles manufactured between 2014–2018 and even recalled certain models. The 2021 Chevy Blazer should be included in the list because failures of this part can lead to harm, injury, or loss of life. The documented defects in older GM models is consistent with my experience. I got oil changes and service regularly. The dealership should not have been so quick to dismiss the the brakes, knowing the history of these parts and the warning signs. This issue should be taken seriously as it is likely more widespread and is a ticking time bomb. Loss of life should not be the catalyst to trigger action in this situation. Other consumers are likely at risk without knowing it.

Filed Jun 17, 2025 · Brakes, Engine · CA

I am reporting a serious safety concern involving my 2021 Chevrolet Blazer, which experienced brake failure while driving, without any warning lights or diagnostic alerts from the vehicle’s onboard system. This created a highly dangerous situation for myself and others on the road. Prior to this incident, I brought the vehicle to the dealership after consistently hearing squealing or screeching noises when braking. The issue was dismissed and attributed to a change in federal regulations limiting the use of copper in brake pads—without any further inspection. This resulted in a missed opportunity to diagnose what appears to be a deeper mechanical failure. After the brake failure, service technicians discovered that the vacuum pump had failed, which impacted braking performance and also caused engine damage. While I’ve since learned that GM has acknowledged vacuum pump failures in several vehicles manufactured between 2014–2018 (via formal recalls), the 2021 Chevy Blazer is not currently included in those campaigns However, the symptoms and outcome I experienced are strikingly similar to the documented defects in older GM models. The lack of early diagnostic detection, coupled with dealership dismissal of clear warning signs, signals a potential emerging safety defect in this newer model that may not yet be officially recognized. Given the safety-critical nature of the braking system and the failure of both mechanical and procedural safeguards, I strongly urge the federal safety agency to investigate whether this issue is more widespread in recent GM models, including the 2021 Blazer. Other consumers may be at risk without knowing it.