GMC Sierra 1500 brake failure problems

Filed Aug 23, 2026 · Brakes · CA

On [XXX], while driving my 2025 GMC Sierra 1500, VIN [XXX], near [XXX], California, the vehicle suddenly experienced a severe brake failure while traveling on a public roadway. When I attempted to apply the brake pedal, the vehicle failed to brake normally and I was unable to safely stop the truck using normal braking. I was forced to reduce speed and allow the vehicle to coast until I was able to enter a side road and bring the vehicle to a stop. I was extremely fortunate that traffic conditions were light at the time. A vehicle traveling in front of me, an intersection, pedestrians, or heavier traffic could have resulted in a serious or fatal crash. After stopping the vehicle, I discovered a metal retaining ring/clip on the floor directly underneath the brake pedal area. At approximately the same time, multiple brake system failure and warning indicators illuminated on the instrument panel. I immediately contacted GMC through the vehicle's SOS system and reported the brake failure. The vehicle was subsequently towed and delivered to a GMC dealership/service department for diagnosis and repair. This appears to involve the mechanical separation or detachment of a component associated with the brake pedal assembly. I have retained the metal component, video evidence of the condition and warning lights, towing information, and dealership repair documentation. A sudden loss of braking caused by the separation of a brake pedal component presents an immediate and potentially life-threatening safety risk. I respectfully request that the federal safety agency investigate this failure and determine whether similar failures have occurred in other 2025 GMC Sierra 1500 vehicles. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Aug 12, 2026 · Brakes · 29,000 miles · PA

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed; however, the brakes failed to respond as needed. The vehicle was towed to the dealer to be diagnosed. The vehicle was diagnosed with an inoperable battery, which caused the brake module to fail, preventing the brakes from operating as intended. The vehicle was repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 29,000.

Filed Aug 11, 2026 · Brakes, Driver assistance · NM

June 29, 2025, Driving on the St. Francis loop in Amarillo, TX, brake lights start flashing, the warning sounds happening, no brakes. I had already slowed down to 35-45 mph due to road construction ahead. I weaved through the cones and as soon as possible, hit the ditch and then coasted to a stop. (I didn’t think about the emergency brake, in my panic.) I turned the vehicle off and called my husband. I decided that I wasn’t pulled over far enough over in the ditch, so I started the pickup again. The lights and warning signals for the brakes were gone and when I pressed on the brake pedal, there were brakes again. I drove home at 35 mph, knowing I could use the emergency brake at that speed, if needed, and had brakes all the way home. GMC Bender repaired truck. After driving approximately 3 miles since repaired, our daughter took the truck to Grease Monkey. She was at the garage door; employee said the pickup didn't need an oil change. She backed out and didn’t have brakes (no warning lights or sounds) and as the truck continued backing, it hit the Grease Monkey sign at the east end of their lot and broke it, knocked the sign over. An employee walked over to see what happened, she told him that she didn’t have brakes. He sat in the pickup seat and pushed on the brakes and said, yes, you don’t have brakes! The police were called, and the officer who showed up took pictures, gave us his card, talked with my husband and talked to the Grease Monkey boss. August 6, 2025, I called GMC Bender Service Department (11 mins. 8 secs.) I told them what had happened. They sent a tow truck to bring the pickup back to their shop. September 16, 2025, my husband texted me saying GMC Bender said that the pickup shows another EBS Modulator Fault. No new parts… used one would be $1293 installed. A week to get it here, no guarantees. There's more details, but the vehicle cannot be repaired to guarantee brakes will work properly. Please help us know what to do next.

Filed Jul 24, 2026 · Brakes, Steering · GA

Vehicle: 2021 GMC Sierra SLT | VIN: [XXX] Dealership: Carl Black GMC Roswell, GA (11225 Alpharetta Hwy, 30076) | Invoice #[XXX] | Service Date: [XXX] Paragraph 1 – Suspension Hazard: Dealership diagnosed a worn left upper ball joint (popping sound on left turns) and installed Rough Country aftermarket upper control arms on my stock-height Sierra SLT. These arms are designed for lifted suspension and alter factory caster/camber geometry, placing extreme stress on ball joints. This can cause sudden ball joint separation, wheel collapse, and total loss of steering control at speed. The dealership admitted on the invoice they "could not find branding" on original parts and chose non-OEM lift components without my consent or any safety disclosure. Paragraph 2 – Brake Failure & No Safety Warning: The same service included a full front/rear brake job (pads + resurfaced rotors) using their certified technicians and parts. After pickup, the brakes failed to operate properly. When I returned, the service manager refused to correct their own workmanship and instead quoted $1,900 to repair the very brakes they just serviced. Most critically, at vehicle pickup they issued no written or verbal safety warning—no "do not drive" instruction—despite the brakes being knowingly compromised, endangering me and the public. Paragraph 3 – Requested Action: The service manager was unprofessional, condescending, and refused accountability. I request an immediate the federal safety agency investigation into Carl Black GMC's unauthorized use of lift-kit suspension parts on stock vehicles, failure to warranty their own brake service, and reckless omission of safety warnings at delivery. This dealership pattern poses an imminent public risk. Please escalate. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 29, 2026 · Acceleration, Brakes · 80,000 miles · MI

The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle decelerated to 30 MPH. The check engine warning light was illuminated. The vehicle was taken to a local dealer, where it was diagnosed, and determined that the timing belt needed to be replaced. The part was on back order. The vehicle was not repaired. The contact stated the vehicle previously experienced brake failure, sensor failure, and glow plug failure. The manufacturer was contacted, but no assistance was provided. The BBB referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 80,000.

Filed Mar 13, 2026 · Brakes, Steering · TX

Vehicle experienced a catastrophic mechanical failure characterized by a percussive "shotgun blast" noise from the rear chassis, followed by an immediate, total loss of braking power (pedal to the floor) and a violent loss of directional stability. This incident represents an aggravated safety failure of known GMT900 platform defects. The technical chain of causality began with the factory exhaust manifold fasteners suffering a metallurgical shear, a universal defect documented under GM Bulletins 19-NA-218, PIP5075, and PIP4701. This shear created a high-velocity, high-heat exhaust leak directed at the brake master cylinder and vacuum assembly. This "heat soak" event compromised the engine-mounted mechanical Brake Vacuum Pump (Recall N192268490 / the federal safety agency 19V645) and destroyed the internal seals of the Master Cylinder (Special Coverage 15143 / the federal safety agency 11V599), resulting in total depletion of vacuum assist and hydraulic pressure. Simultaneously, the "shotgun blast" and violent swerve were caused by structural failure consistent with Rear Brake Caliper Bolt Fracture (GM 13247 / the federal safety agency 13V342) and Rear Axle Shaft/Pin Fracture (GM 14892 / the federal safety agency 14V819). This mechanical collapse caused the caliper to strike the wheel, resulting in a catastrophic rim blowout and immediate loss of tire pressure. Despite the vehicle having aftermarket long-tube headers installed, the root cause of the heat-related brake failure was the failure of the OEM GM manifold fasteners which snapped off in the cylinder head, as documented in the aforementioned bulletins. Under the Magnuson-Moss Warranty Act, the manufacturer remains liable for these pre-existing safety-critical defects. The vehicle is at Glenn Polk Chevrolet for a 901-series Product Allegation Investigation (Case #90199492). This report is filed to demand federal oversight into these life-threatening defects. The combo of failed fasteners, rim blowout, and compromised braking created a vehicle that was both unable to be steered or stopped

Filed Mar 11, 2026 · Brakes · GA

I was out one day for lunch and my brakes stopped working on my truck. I had the truck towed after I limped home in it. The master cylinder failed at 4,200 miles causing the brakes to fail. It was replaced by the dealership.

Filed Mar 2, 2026 · Brakes · NM

I had and still have the Brake Assist failure warning light on and having issues with brake pedal effort not working as it should to stop vehicle and also the stability control warning lights., the brakes hardly work at all at low speeds and most of the time don't stop the vehicle almost causing several crashes. I took vehicle to gm service center and they said they updated software but when I picked up the vehicle and drove it not long after the brake assist warning came back on and I still had no brakes at slower speeds and the problem had actually gotten worse than it was before i took it to them. I called the dealership and told them that the problem had not been fixed and it was worse they said that I would have to pay the service fee / price for parts if I wanted to bring the vehicle back in and to have problem fixed...I explained it was a re call and it was taken to them to have issue fixed in the first place ...and I was told I would have to pay since they updated software ..I then explained it was worse than when I took it to them and still got denied any kind of resolution to the problem. Nothing was fixed or solved. I still had the warning lights on dash and the problem was worse then when I took the vehicle to them for repair. Not long after the transmission went out and the vehicle hadn't been drove. So it sat for 2 yrs or so. I just got a new one put in and the vehicle still has the same problems with the brake system . I reached out to dealership once again and was told I would still have to pay to have the issues fixed when it was never taken care of by them to begin with.

Filed Feb 20, 2026 · Brakes, Driver assistance · NV

The brakes suddenly activate and cause the vehicle to rapidly stop with no warning of any kind and without any braking action being taken by the driver. Then, the brakes do not release and the vehicle cannot be moved as the brakes remain on. Turning the engine off and then restarting it or shifting to other gears does not release the brakes. The vehicle remains immobile and cannot be driven. After a few hours have passed, like overnight, the brakes release and the vehicle can started and driven just as if nothing had happened. A message briefly appears on the vehicle information screen each time this inadvertent braking occurs. It reads, “Brake Failure System”. These brake lockdowns occurred when driving on streets and in the driveway. No accident resulted but could have easily occurred. This is dangerous for a driver and occupants of a vehicle with this safety flaw as well as for other people and vehicles in the vicinity. This has happened five times. The last two instances resulted in the vehicle being loaded onto a tow truck and taken to a dealer of the vehicle’s manufacture. Thus far the dealership has not found what may be causing this intermittent braking problem.

Filed Jan 12, 2026 · Brakes · ME

While traveling at low speeds in parking lots and in the operation of parking, my 2016 GMC Sierra 1500 gets a hard brake pedal that goes to the floor but I have no brakes. I almost hit a person in a local grocery store parking lot, at the bank driving up to the ATM, and I almost lost my truck over a bank because the brakes failed. This has happened multiple times at low speeds but it is getting more consistent recently. It has endangered myself and others. It is only a matter of time until damage occurs or someone gets hurt.