After parking and backing up when I hit the brakes, they got hard and did not operate properly. When pulling forward the brakes were hard to operate and barely stopped the vehicle. After sitting a while and restarting the truck they operated as they should have. Not sure if this is an operable safety issue but, it was very concerning that the brakes did not operate properly.

- Hartsville, SC, USA

I live in Oregon, my truck that I purchased from a private owner from Utah in June of 2019 had 37,300 miles today's date March 1 2020 my truck has 39,100 miles. A couple of days ago I changed to my Oregon license plate. While under the truck I noticed a lot of rust on many parts of the brakes, suspension and frame especially when I lowered the spare tire which showed severe rust damage. This truck has an extreme amount of rust for a vehicle built in 2017. I consider this to be a safety hazard especially because drivers use this type of truck to haul or tow heavy loads.

- Lake Oswego, OR, USA

Truck was recalled for brakes. Recall completed was computer issue. That recall caused brake vacuum to malfunction. Almost cost me my life. 70 mph in dallas tx traffic. Had to slow down quickly. Once it slowed down then it wouldn't stop!!! got it to a parking garage almost hit 3 vehs. It was traumatic. GM knows about this issue. Many others have reported. Not happy!!!!! GM extended the brake warranty to 150000 miles. That makes me feel better. They put same part back on. So I guess it will happen again. I'm very leary of my truck.

- May, TX, USA

Noticed mushy, vibrating brakes. Took it to tire store and was advised the brake booster and vacuum pump are bad. I've had several close calls in parking lots, as the vehicle is slow to resond to the application of the brakes. The drivers seat is also loose. It moves from side to side as I go around corners. I'm afraid it will come off the rails or worse yet, not secure me in the event of an accident.

- Placerville, CA, USA

My 2017 GMC Sierra denali had already been the subject of the recall relating to the brake issue. Shortly after they performed this recall work the brakes began failing at low speed. When driving below 5 mph, the pedal which suddenly fall and the ABS would trigger. During this time, the car would continue moving with the ABS fully vibrating. Thankfully, my trailer hitch absorb the rear impact against a wall. The problem continued. I then took the truck in for service and they reported that there has been a significant failure rate of the vacuum assist. The dealer replace the vacuum pump and vacuum lines. I'm extremely concerned that this would happen to someone else near an intersection, not just slowly backing into parking spaces. I have contacted GMC by email but still have received no response or acknowledgment of my communications.

- Greenville, SC, USA

My brakes are not working to its full potential. I believe my vacuum pump is going back on my truck. I noticed last week that I was driving out of a parking lot and coming to a stop sign and I pressed my brakes and it was not working properly. I had to release the brake and slam on the brakes again almost causing a accident with incoming traffic. I called all my local dealerships and stated that there was no recall on this just yet for my truck, but there is a recall on the vacuum pump. They stated they already did the software update to my truck back in September 2019. My truck was going maybe 10 mph to a stop sign and I applied my brakes once and was not completely stopping, so I took my foot off the brake pedal, and it got worse and I had the brakes pressed all the way down to the floor. This is not safe! this is my daily driver and I drop my kids off to school every day and its not a good feeling knowing my brakes can go out at any time!

- Creedmoor, NC, USA

Reference the complaint number 11306627. The vehicle had the brake recall notice N192268490 complied with at the dealer in November 2019. The vehicle then experienced a brake failure in February 2020. Please add this information to my original complaint.

- Saint Charles, IL, USA

In my driveway on dry pavement at slow speeds when pressing the brake pedal the vehicle does not stop satisfactory. The brake pedal was then pressed until it was very hard the vehicle continued to move but slowly began to stop. When pressing the brake pedal to the maximum and a firm pedal a noise could be heard from under the hood. The noise sounded like a moan, similar to the brake anti skid system being activated. I was able to simulate this braking problem multiple times while backing up and moving forward at slow speeds. Cycling the ignition on and off did not correct the problem.

- Saint Charles, IL, USA

Brake vacuum pump failure. Vehicle brake pedal becomes very hard to depress at slow speed and very hard to stop. Usually happens when in slow traffic and after the pedal is depress more than 2-3 times in a row.

- High Point, NC, USA

October 2019 went to the dealership to have breaks worked on given recent recall about the mechanical vacuum pump output may decrease over time, decreasing the amount of vacuum/power brake assist. However, shortly after getting the recall done on my truck (1 week later) I was in the parking lot backing up out of my parking spot and the break pedal became really stiff and I couldn't push hard enough to stop the vehicle from moving. I just kept rolling until I hit the curb. So far this has happened a dozen times and all when I was moving about 5 miles an hour the exact same way, pedal becomes stiff and I couldn't stop the truck from moving. I feel like things are worse now after getting the recall done. This was never an issue before and as I look at the recall notice, it state incomplete, telling me possibly the manufacture knows there's still an issue but no fix has been done yet, even after 4 months.

- Wichita, KS, USA

Vehicle frequently exhibits loss of braking power. When this occurs, something sounding like the ABS systems is sometimes engaged by the vehicle and other times not. While GM claims braking performance meets federal standards, the braking power is greatly reduced when the hydraulic system is engaged and almost non-existent when neither vacuum pump nor the hydraulic system functions. Even if the braking performance meets federal standards, it creates a dangerous situation when the driver is not expecting a failure. A GMC dealership has admitted there is an issue and recommends replacing the vacuum pump but has been unable to source the parts in over two weeks and has no eta for when the part will be available. Meanwhile the braking power loss condition occurs every time the vehicle is driven. During the first instance, I was towing a travel trailer in stop and go traffic down a 7% grade. Had it not been for the trailer brakes, this could have been catastrophic. The second occurrence involved backing into my driveway and nearly causing a collision because of poor braking performance. Now that I fully aware of the issue, the vehicle is driven sparingly (only when absolutely needed) and with great care. The characterization of this issue by GM as not being a grave safety concern is inaccurate. Their inability to source parts in a timely manner is inexcusable.

- South Jordan, UT, USA

First and most importantly my brakes are my main issue and safety problem. I nearly ran into the car in front of me at a busy intersection. My trucks brakes lose pressure after the first initial stop coming to any traffic lights, stop sign, slow traffic, parking lots etc... no matter how slow or fast the trucks movement is. First break attempt is ok but 2nd starts losing pressure and 3rd attempt is complete lost of pressure anf and the truck just rolls until it slowly comes to a stop. I worry about the safety of myself and others motorist regarding this issue. My second complaint is my driver side mirror. Every time I get into my truck and start it. My driver side mirror moves out of its setting and I constantly have to fix it.

- San Antonio, TX, USA

The past month as I push on the brakes driving on the road my steering wheel starts to shake as the brakes are being applied. Does not happen all the time has actually only happened 3 times in a month.

- Coolidge, AZ, USA

While braking pedal feels like gurgling and at times complete loss of power assist making pedal very hard to depress all were in motion and intermittent making dealer diagnosis difficult and not yet able to replicate so dealer refuses to do work

- Bartow, FL, USA

For NHTSA recall 19V645, why did NHTSA accept a 'reprogramming' of the functionality to 'band aid' the issue rather than requiring replacement of the vacuum pump, which is the identified defective item?

- Kathleen, GA, USA

As I was backing up I applied my brakes and for some reason nothing happened which resulted in my hitting my wife's car and damaging her drivers side quarter panel. When I asked GMC about the issue they said it was just an error on my part. Now I find out that there is a recall on the braking system that the pressure to the brakes may be affected. Who is responsible for the damage to her car?

- Meyersdale, PA, USA

Was driving my 2017 GMC Sierra with my wife and young son. I went to stop at a red light and had no brakes. The brake was very hard to push and made a funny clicking noise when I shoved it to the floor. I was barely able to avoid a collision and pull into a parking lot. I noticed then, that the service brake assist light was on. The truck gave no prior warning that anything was wrong. This was a very scary situation that could have resulted in a terrible accident.

- Worton, MD, USA

While driving on the highway at 70mph, a service brake assistant warning came on. The brakes at that point were extremely difficult to use and there was no way for a quick stop. Was able to get to a dealership where they had to replace the master cylinder, the booster pump, vacuum pump and tubing. Cost for the repair was over $1,200.

- Houston, TX, USA

I almost killed a kid today parking for a baseball game. I was traveling slowly and parking when my brakes became hard to push and failed. Truck went over curb and toward kid putting on his cleats and not facing me. I was able to push as hard as I could and it stopped. I backed up and brakes worked again. I have 46,000 miles on the truck. I am now afraid to drive it, but it seems they are working again. If this is common, GMC needs to take care of this. Someone will soon be hurt seriously!

- Decatur, AL, USA