Brake pedal becomes extremely hard to depress. The vehicle fails to slow down at a reasonable rate even when very significant (foot) pressure is applied. This occurred now four times; three occurrences when backing up and one occurrence when driving forwards. All of these event occurred at very slow speed, basically when moving the vehicle into a parking spot. All events were preceded by slow driving (< 3 mph) for about one minute. The loss of stopping power occurred suddenly; even a few seconds before there appeared to be no issue. The issue remained until I put the car in park and turned of the engine. The issue was no longer there when I restarted the engine. The instances of the issue occurred over the last two months. Initially it was ignored as an individual occurrence, yet the three additional occurrences indicate an issue. A similarity of the conditions leading up to the issue is that I drove very slowly on a flat (level) surface. The duration of this drive was maybe a minute or so. (the best way to describe this is how one drives when looking for a parking spot in a busy parking lot with lots of pedestrian traffic).

- Katy, TX, USA

When I am going at a slow rate of speed at fast food drive-through or backing down my driveway in reverse I go to press on my panel and next thing you know it is is hard as a brick and the vehicle keeps going I hold most didn't stop going down my driveway and hit one of my children I've took it to the dealership twice they say you can't tap your brakes you have to let the vacuum build back up that is no excuse for the vehicle not stopping!!!! this happens daily at some point something has to be done someone is going to get hurt !!!!!!!

- Cincinnati, OH, USA

Brakes become stiff at slow speeds now allowing the truck to properly stop

- Rancho Cucamonga, CA, USA

When attempting to stop at low speeds, experiencing little to no brake pressure in drive and reverse. This is the third occurrance since Nov 2018. Symptoms include stiff brake pedal and audible click upon resuming motion and thump felt in brake pedal followed by significantly reduced braking ability. Narrowly avoided three collisions on commute to work this morning in normal traffic conditions.

- Virginia Beach, VA, USA

At low speeds the vacuum pump gets weak and does not provide the needed vacuum to the brake booster. Resulting in loss of power brakes. While parking I backed up and then pulled forward to straighten up. As I changed direction a pedestrian walked out in front of me and nearly hit them. I had to stand on the pedal with both feet. If my wife would have been driving the truck she would have ran the pedestrian over. The dealer can not replicate the problem and they are not going to replace the booster under warranty. Although GM does have a technical service bulletin in place about this exact issue. Tsb # pit5361C. This is a major safety concern!!!! and GM does not care!

- Johnson City, TN, USA

The contact owns a 2016 GMC Sierra 1500. The contact stated that the vehicle failed to respond when the brake pedal was depressed. The contact had to apply force to the brake pedal each time the failure occurred. Ourisman Chevrolet Buick GMC of alexandria (1800 old richmond hwy, alexandria, va 22303, (571) 366-8047) was notified several times for months and stated that further diagnostic testing was needed. The vehicle was not repaired. The contact stated that the vehicle experienced the same symptoms as listed in NHTSA preliminary evaluation number: PE18012 (service brakes, hydraulic, service brakes), but was excluded. The manufacturer was notified of the failure. The failure mileage was not available.

- Fort Washington, MD, USA

Lost power brakes when depressing them as I was backing into a parking spot. I had to press repeatedly to get pressure back in the brakes. Luckily stopping in time. It happened again later this evening when I was rolling to a stop at a light. The brakes again lost power and I had to press them repeatedly stop the truck before hitting the car in front of me.

- Lees Summit, MO, USA

The contact owns a 2016 GMC Sierra 1500. While driving various speeds, the brakes suddenly malfunctioned and the brake pedal became very difficult to depress. The vehicle was taken to coathella valley GMC (78960 garner rd, indio, ca) where it was diagnosed that the brake vacuum pump was faulty. The vacuum pump was replaced, but the failure recurred. The manufacturer was not notified. The VIN was not available. The failure mileage was 143,000.

- Coachella, CA, USA

When traveling at slower speeds in stop and go traffic on the highway the brake peddle becomes very hard and I am unable to stop the truck. No other vechiles were hit, but it was a very uncomfortable situation. This has also happen servel times in forward and reverse within public parking lots. I have been a able to determine the truck loses power brakes when the brake peddle is applied 4-5 times while traveling slow.

- Dacula, GA, USA

The contact owns a 2016 GMC Sierra 1500. While driving at low speeds, the vehicle would not stop in a timely manner when the brake pedal was depressed. The contact had to depress the brake pedal several times to stop the vehicle. The vehicle was taken to ron anderson Chevrolet Buick GMC (464054 E state road, yulee, fl, (904) 572-4132) where it was diagnosed that the brake vacuum pump failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 41,000.

- Yulee, FL, USA

The contact owns a 2016 GMC Sierra 1500. Within less than a week of owning the vehicle, the brake pedal felt hard and was difficult to depress. Corwin Chrysler Dodge Jeep Ram Fiat (1025 w sunshine St, springfield, mo 65807, (417) 862-9272) was informed, but the vehicle was not diagnosed or repaired. The vehicle could not be driven safely due to the failure. The dealer stated that the vehicle may be serviced per a warranty, but it would not be in effect for another sixty days. The dealer stated that the vehicle may be serviced for tsb: Pit-5361B (additional brake pedal effort). The manufacturer was not notified. The approximate failure mileage was 71,000.

- Pierce City, MO, USA

2016 GMC Sierra- bought used hard shifting noted immediately and shuttering on inclines, took to dealership had part replaced- fixed shuttering but not hard shifts- now it not only shifts hard but while I was trying to stop at a drive through the brakes failed- lunges forward almost hitting the car in front of us- next day I pulled into a parking spot same thing happened- brakes would not compress- stood on the brake before it finally stopped- backed up a bit to straighten up and the [xxx] thing did it again in reverse. I'm traveling back home to Arkansas from Florida in a few days with my children and I'm scared to death to drive this thing. I can't get it looked at before we leave because of the weekend/ christmas break.seriously unsafe vehicle! there should be recalls on these vehicles! I've read so many similar stories, why has this not been addressed yet? GMC should be ashamed. Parts of this document have been redacted to protect personally identifiable information pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Hot Springs, AR, USA

I have experienced loss of power brake boost on numerous occasions, several times while backing my boat trailer down the boat ramp, and several occasions backing up at slow speeds and going forward at slow speeds (usually less than 5 mph). The brake pedal becomes very hard to depress, and truck feels like it's not going to stop unless I apply extreme pressure. It has been intermittent. I asked my local GMC dealer about the issue this past fall, and was told they couldn't do anything until it failed and could be replicated. I didn't experience it again for several months, but this week it has occurred at least three times. I called dealer to make an appointment, which they did, but they again told me that unless they can replicate it, they won't be able to fix it. I have researched this site and have found a number of instances with both GMC Sierra's and Chevrolet Silverado's experiencing the exact same problem.

- Guilderland, NY, USA

Pulling into my garage at very slow speed, I depressed the brake pedal and nothing happened. I had to stand on the brake pedal to prevent the truck from going through the wall and into the dining room. Thought maybe there was some air in the brake fluid. Looked at the reservoir and nothing appeared out of normal. A couple of weeks later, today 12/18/18, while backing out of a parking spot at an autozone, someone walked behind the truck. As I pressed the brake pedal to stop and allow them to pass, nothing happened. The truck kept going. I had to stand on the pedal to prevent my truck from bumping into the pedestrian. Both incidents had the vehicle moving at less than 5 mph and idle engine power.

- Collierville, TN, USA

Brake pedal becomes hard to push making stopping a problem. Huge safety issue. While in motion at low RPM brake pedal becomes hard limiting the stopping of the truck

- Dilliner, PA, USA

My 2016 GMC Sierra has 44,000 miles on it. In the last 2 weeks I have had 3 occasions when traveling at very low speeds the brake pedal becomes stiff and requires both feet to depress enough to get the vehicle to stop. Even when completely compressed with my full force the vehicle continued to roll slowly. One time was in a parking lot and the other 2 times were at drive-thru fast food spots. Brake function seems completely fine at normal operating speeds. A search of the internet led me to find several forums with people describing the exact same situations. At low speeds the brake pedal becoming extremely stiff and cannot be depressed more than 1". I was lucky to be able to stop by putting my truck into neutral. If I had rolled out in cross traffic someone could have been killed. There are way too many stories exactly like mine all over the internet for there not to be a significant problem with the vacuum pump and or brake booster or some other brake system component on 2014-2018 GMC pickups and large SUVS.

- Sherwood, AR, USA

Vacuum pump failed and replaced at my own expense. Brakes would not depress, were very firm and truck continued to roll even with extra firm pressure on brake peddle.

- Irvine, CA, USA

Had to replace vacuume pump after intermittent brake failure at slow speeds with only 38,000 miles on the truck. Brake failure would occur without warning. Dealership diagnosed the issue after testing he vacuume pump, which was reading 6 psi. Was told there have been no recalls for this issue.

- Edmond, OK, USA

Several times I've experienced weak braking a different speeds or while shifting from parking. I also experience the brakes not fully depressing after I step on the brakes. I took my vehicle for a brake inspection thinking I may need new brakes and was told by the inspector that the pads are not the issue, he told me he has never seen an issue similar to what is going on with my truck and instructed me to take it to the dealership. When I contacted the dealership the service advisor told me that it sounds like I just need to replace the brake pads and rotors and told me that he doesn't believe there's an underlying issue based on what I was told at the other service center. Any issues with braking components should be addressed immediately by the manufacturer before people get hurt or someone is killed.

- Palmdale, CA, USA

Brake pedal rock hard and will not press down

- Kenosha, WI, USA