Brakes become very hard to press in traffic and while backing up. The condition worsens with multiple presses of the brake pedal. The stopping distance of the truck in increased even with increased pressure on the pedal. The truck has 28,463mi. I contacted a dealership and they will not cover this repair. I have ordered the parts and will perform the repair myself. GM has issued a service bulletin on this pit5361B.

- West Bridgewater, MA, USA

Brakes appear to lose boost when stopping. Have to press peddle with both feet. This has happened on three separate occasions.

- Leesburg, GA, USA

At slow speeds from a stop if you let off the break pedal and immediatly reapply there seems to be extremely hard breaking. Almost impossible to stop the car.

- Greenlawn, NY, USA

On several occasions the brake pedal becomes difficult to depress. Releasing the pedal and depressing again corrects the problem. Today while exiting a parking space at low speed to avoid collidiong with ann approaching vehicle it took both feet to depress pedal. I am a 200 lb. Male. I am not sure a small female could have corrected the failure in a timely manner.

- Charleston, SC, USA

When I press on the brakes, it feels as though the master cylinder is gone and it is the manual type drum brakes that has air in the line. It takes everything I have to press them and pray it stops!! the vehicle is always in motion when detecting this problem and seems to occur more repeatedly if the brakes are pump quickly in succession before applying brakes or when the brakes are pressed for an extended amount of time then you release and repress it want stop. Another issue is my lane id warning. When turned on at the button, it just beeps at me and shows service light. When I first took it in with the problem, the dealership called me and said all fixed, but it did it before I left the parking lot. They had my truck all day for the issue, put me out of a vehicle and then said they would need for extended time to repair but didn't know there was problem. How do you make that determination when you told me its repaired. I just turned it off and haven't used in 2 years.

- Ellisville, MS, USA

The contact owns a 2015 GMC Sierra 1500. While driving at a low speed or while idling, the brake pedal was depressed and failed to engage. The contact stated that the failure was also evident while driving in reverse at a low speed. The vehicle was not diagnosed or repaired. The local dealer and the manufacturer were not notified. The vehicle was not included in NHTSA campaign number: 14V339000 (steering, service brakes, hydraulic). The vehicle was not repaired. The approximate failure mileage was 55,000.

- Red Oak, TX, USA

During low speed braking maneuvers while parking in my driveway brake pedal pressure required to stop became very hard. It took both feet on the pedal to actually stop the truck. This would happen daily while backing in to my driveway. Also during normal city stop and go driving it would also require great effort to stop the truck and the pedal would be very hard to press.

- Lakeview, AR, USA

Complete brake failure with no warnings. Dealer diagnostic reports frozen vacuum pump. The condition was encountered in motion on a county rd.

- Elkton, MD, USA

Vehicle loses brake pressure while moving at slower speeds. Once coming to a stop, then doing slow speed stops and starts the pedal will become hard and requires great effort to bring the vehicle to a complete stop. Issue started at about 38,000 miles just after factory 36,000 mile warranty. Issue presents itself more often in reverse while backing in, especially if grade is sloped. Have had multiple close calls in parking lot settings while trying to back in to a parking spot or inch forward. A friend had this same issue with his 2016 Chevrolet Silverado, which ended up being a $1,800 fix through the dealership. He was told that it was a vacuum issue with the brake pump and that a recall would probably be issued. I have been holding out on service in hopes of this recall being issued.

- Fenton, MI, USA

Hard brake pedal - "no brakes" first occurrence in paring lot 2016 timeframe. Was backing into a spot that was slightly downhill, no brakes, vehicle hit curb and stopped. Pulled forward no brake, eventually they came back. Complained to GM hotline - they responded with questions and I told them I took truck to dealer, I believe dealer replaced master cylinder second occurrence May 2017 driving on I-75 - 18 year old daughter driving on way home from college, traffic slowed and she said "I have no brakes, pedal wont move". she maneuvered to side of road, vehicle turned off and then back on, brakes came back and worked ok. Mentioned during oil change at serra Chevrolet, but since brakes were working they would not investigate third event - November 16-- at tail end of 8 hour drive returning from deer camp. Exit freeway and in stop and go traffic, on a downhill portion of road, the brake went hard. Got vehicle stopped and turned engine off and back on, brakes released. Contacted dealer about bringing truck in this week. Going to ed rinke dealership today Nov 24, I read article about the a faulty brake vacuum pump. This now makes sense. Please get this issue fixed

- Bloomfield Hills, MI, USA

Stopped to take a break while traveling. As we went to exit the parking area and stop at the stop sign, no real braking power. Had to put both feet on the pedal and press into it to come to a stop. We were traveling at about two mph. No warning there was a problem. One minute we had good brakes, the next, not. Luckily there was no traffic, as we were unable to stop at the stop sign and finally came to a stop in the right lane if the road. The mechanic stated the reed in the valve of the pump came apart.

- Grand Rapids, MN, USA

In stop and go traffic on highway at low speed experienced brake pedal stiffening and difficulty stopping. Reoccurred several times during same traffic pattern but only at the low stop and go speed. Problem occurred with no warning. Brakes worked as normal under other circumstances. Forum research suggested this was a vacuum pump and occurred to other models of same year and millage. Vacuum pump (internal) failure was confirmed issue by GM dealer and replaced. Mileage when problem occurred was approximately 47,200 miles. Vehicle in good condition, no wrecks, regular maintenance, and not used for towing or heavy hauling.

- Kings Mills, OH, USA

I first noticed the issue on the morning of Saturday, November 10th as I was backing into a parking spot. As I was backing in, I noticed all of a sudden the brake pedal was on the floor and I was about to plow into a curb and threw the truck in park. I didn't think anything of it. The second time it happened was one day later as my fiance and I had just completed a 200 mile drive home. I was pulling into the parking lot at our townhouse complex and as I was pulling forward to back into the space, I noticed I had no braking power whatsoever. I had to throw the truck in park to keep it from hitting a neighbors vehicle. I opened the hood with the engine running, and noticed a ticking noise I hadn't heard before and my brake pedal only had about 1/4" of travel left. I could pull the pedal back to where it is supposed to be but it would just fall back down to the floor. I was able to very slowly and carefully park the truck using park and the parking brake. With the engine still running and the vehicle in park, I depressed what was left of the brake pedal and held it to the floor and heard a moaning noise coming from the area near the master brake cylinder and could feel the brake pedal shuddering under my foot. I feel unsafe driving this vehicle and I was giving no warning of the brake failure. I am having the vehicle towed to sewell Buick GMC in dallas and will update when they find cause. I will also be calling GM customer support as I feel this is a huge safety hazard.

- Dallas, TX, USA

When going under 15mph brake pedal becomes hard and doesn't work. Vehicle has 50K miles. Brake booster declared bad by mechanic. This issue almost casued accident.

- Georgetown, KY, USA

Truck looses braking ability at low speeds such as traffic or parking lots.

- Fairfield, CA, USA

Issue when braking that causes the brake pedal to lose power and causes the driver to depress the pedal extremely hard to have the brakes engage. The cause appears to be a faulty vacuum pump that requires replacement. This could be potentially a large safety issue if the pump fails and the vehicle is unable to be stopped in time to avoid a possible collision. This issue has occurred both while in traffic on a city street and while attempting to park the vehicle.

- Baton Rouge, LA, USA

The vacuum pump controlling the brakes has failed. When the brake is pressed in stop/go traffic, it will first stop the vehicle, but if the brake is released then pressed again, the brakes will not work and the vehicle continues to roll forward. A mechanical/electrical noise can be heard before this occurs. This is more noticeable on wet roads or roads with a steep decline.

- Hixson, TN, USA

At low speeds (parking speed, school pickup lines, creeping traffic speed) the brake pedal will lose all boost pressure. The brake pedal becomes extremely stiff and ineffective. This situation occurred on a few occasions and caused great alarm with myself and my wife. Great potential exists for an accident involving machinery, animals or human beings. The vehicle was taken promptly to the local GMC dealership for service with a copy of GM service bulletinno.: pit5361B. The dealer kept the vehicle for several days to perform an existing safety recall for steering anomalies (recall # 18289) as well as diagnose and repair the brake boost issue. Service bulletin pit5361B was followed and the vacuum pump assembly was replaced to resolve the brake boost issue. This repair occurred at 40728 miles - just beyond warranty coverage terms. Total cost of repair $686.56. The brake boost issue has not reoccurred to date since the repair. This vehicle is not abused or involved in any rigorous activity. It is a general use vehicle and is used primarily for family errands and road trips.

- Aledo, TX, USA

When brakes are applied the pedal is hard and vehicle does not stop. It seems to happen when going slow for example in parking lots etc. I have read other articles where people are experiencing same thing at high and low speeds. It does not happen all the time, but it started 11/2017 and I've experienced this four times now and the wife as well.called GM the other morning was told there was no recall for this issue per GM some vehicles were affected but not mine, explaining what I've found and was told to take the vehicle to dealer for diagnostic.asked if it would have to be the dealer cause they were expensive to do diagnostic. Was told yes and it would have to be out of pocket.

- Horizon City, TX, USA

Vehicle is shutting off at any given speed, ie. 35 mph in town or 70 mph on a highway with oncoming traffic. When vehicle shuts off, loss of all control of the vehicle takes place. No brakes, no steering, nothing until the vehicle randomly turns back on. This is not a consistent occurrence to know when it is going to happen or be prepared for it to happen. I watched my husband shoot across the road into the other lane and almost put the vehicle over a bank one night when it happened. This has been an issue since January 2018 for us, we have taken it to the dealer where it was purchased multiple times for them to tell us they can't duplicate the issue and nothing is coming up in their system for an error code. It has caused a major inconvenience for my family, as we don't dare put our children in the truck leaving the responsibility solely on one parent to Transport the kids to and from daycare. I worry for the safety of my husband on a daily basis.

- Pine City, NY, USA