Intermittent extreme loss of braking power - in forward and reverse. Sometimes and unexpectedly cannot stop quickly even when brake pedal pushed to the floor.

- State College, PA, USA

When applying brakes at low speed like pulling out of driveway or away from a gas pump. If the brakes are pumped or pressed hard the brake pedal gives strong resistance and the truck will not stop. In order to stop the truck the emergency brake needs to be applied. The problem is worsened if on a downward incline when taking the truck out of the park position and moving into drive while holding foot on the brake.

- Newton, NJ, USA

First noticed at about 65000 miles. When braking in stop-and-go traffic or in reverse (especially down an incline such as a boat ramp), the brakes can become very hard to press and non-responsive. This results in long stopping distances. Had the truck inspected by dealer and they suggested vacuum pump. After researching this issue, there appears to be a general issue with the vacuum pumps that GM will replace under warranty, but has not recalled....

- Lima, NY, USA

When backing down a steep hill or back a boat down the boat ramp, the brake pedal get hard and the truck doesn't want to stop. Driving on a flat surface I haven't had an issue but it is very scary backing the boat into the water feeling the brakes aren't doing its job.

- Saint Charles, MO, USA

Within about 15 months of ownership my vacuum pump on the brakes malfunctioned, while I was towing a pontoon boat. Needless to say I was very scared that I was not going to be able to stop but eventually I slowed down enough to pull into a gas station in warsaw, in. Luckily when this happened there were very few other vehicles out on the road otherwise this story may have a different ending. This happened on highway 15 in milford, in.

- Aurora, IL, USA

The problem has occurred twice in the last week. Both times in normal driving conditions and good weather conditions. While pulling in my driveway at low speed when I pushed on the brake pedal it was hard and would barely depress. There was no power assisted braking and it took me pressing as hard as possible with both feet to get my truck stopped before I hit my garage. This happened again when I was trailering my 1500 lb fishing boat. I was backing it down the ramp and brakes failed again. I had to again press brake pedal as hard as possible and use emergency brakes to stop. There was a noticeable grinding sound in the brakes while trying to stop. Again as if there were no power brakes. Both instances occurred while going 2 to 3 mph but if it happened in an area with pedestrians or at higher speeds it could result in serious property damage and injuries. Please look into this and force GM to take corrective action asap.

- Taylorville, IL, USA

When brakes were applied the truck would not stop, truck was just out of warranty by weeks, independent shop replaced the vacuum air pump for the brake system. I was lucky that I was moving very slow, in a parking lot, no one was hurt and no damage to the truck.

- Mundelein, IL, USA

The contact owns a 2014 GMC Sierra 1500. While driving at low speeds, the brakes failed to stop the vehicle when the brake pedal was depressed. The contact stated that the brake pedal had to be depressed with force to operate correctly. The vehicle was taken to henson Chevrolet Buick GMC (201 N may St, madisonville, tx 77864, (866) 551-9977) where it was diagnosed that the brake booster vacuum pump needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The failure mileage was 23,000. Consumer stated braking failure happened on the residence driveway.

- College Station, TX, USA

I have had problems with my brakes for the last 3 years. I already had by brakes fixed my GM because of a bad squeak when pressing on my brakes. I recently just changed my master cylinder because the brake pedal would get stuck on certain occasions when driving. Sometimes having me to use the emergency brakes. Sometimes I would have the brake pedal all the way down and the truck would still keep moving. It would happen sporadically. Most of the time when I am driving in traffic or through a parking lot.

- Sugar Land, TX, USA

When braking at slow speeds, like when idling in traffic or rolling through a parking lot, when the brake pedal is depressed it is very hard, like when pressing the brake pedal with the vehicles engine off. At times I have had to used both feet to press the brake pedal the try and stop the vehicle. The vehicle is also very hard to stop when this issue occurs.

- Cartersville, GA, USA

While driving my truck at slow speeds and applying brakes, the brake pedal will get hard and unable to stop vehicle. It has occurred while backing a trailer town hill towards a lake and I was unable to stop the truck only able to have friend block the tire so I could put in drive. It has occurred while approaching stop signs and also frequently in parking lots.

- Morrison, IL, USA

Very hard brake peddle. Limited to no braking ability when condition exists. Going slow backing up with trailer, forward going slow. If foot on brake for extended time at stop light braking ability abates, peddle very very hard. Brakes unable to stop vehicle no matter how much pressure put on brake peddle.

- Andover, MN, USA

The contact owns a 2014 GMC Sierra 1500. While driving 70 mph, the vehicle stalled and the stabilitrak warning indicator illuminated. In addition, the steering wheel and brakes seized. The contact powered off the engine while in traffic. The vehicle was restarted and drove normally. The contact stated that the failure recurred numerous times. The vehicle was taken to covert Buick GMC (located at 11750 research blvd, austin, tx 78759, (512) 583-3411) where diagnostic testing was completed, but no failure code was found. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 103,000.

- Austin, TX, USA

While tapping the brakes, the vehicle's headlights will dim occasionally. 2 times now while tapping the brakes, the entire dashboard (including the touchscreen) turn off and restart. The first time was travelling on a highway and the second time was on my driveway, I applied the brakes and the entire car shut down, including the power steering, power brakes, and engine. That time I rolled out of my driveway and into the road. I was lucky no one was coming

- Mcgregor, MN, USA

My 2014 GMC Sierra is having a major brake issue. I replaced the brake pads after being told the padding was low. This did not fix the problem. My truck does not slow down when braking on a hill. I read in another article that the vacuum pump goes out at a low RPM, causing the truck not to stop. Unfortunately, my wife was driving my truck down the driveway, and couldn't stop. This issue almost caused her to hit another vehicle that was passing at the end of the driveway.

- Conyers, GA, USA

Driving at 55 miles per hour lost brake functions. Was able to slow down on side of high, and had truck towed to nearest shop. Found that vacuum pump and belt were broken. Ver concerned that a belt brakes and you can not stop. Have reported issie to GMC

- South Setauket, NY, USA

While tapping the brakes, the vehicle's headlights will dim. Occasionally, while tapping the brakes, the entire dashboard (including the touchscreen) turn off and restart. On 6/18/18, while travelling on a highway at 40 miles an hour and approaching a red light, I applied the brakes and the entire car shut down, including the power steering, power brakes, and engine. I had to place the car into neutral and turn it back on in order to brake in time.

- Bonney Lake, WA, USA

While driving went to stop at service station brakes would not work as they should, had to push on pedal very very hard to stop almost ran over gasoline pump.dealer says it may be vac leak or pump.very bad situation dangerous GM should repair it my dealer is mitchell Buick GMC in san angelo

- Sheffield, TX, USA

60K miles. Service brake assist light came on after 1 hour drive. At low speeds, brake pedal is extremely difficult to depress (as if no power brakes on antique vehicle), truck does not stop as needed. Diagnostic check from onstar does not show any code.

- Charleston, SC, USA

Vacuum system on the breaks are loosing pressure causing the breaks to become nearly impossible to depress. I have run in to my fence causing minor damage. This happened when I was at a snails pace, couldn't imagine it happening at a higher speed GM is aware of the fix but at my cost of over $750. There have been numerous complaints to the dealerships and on GM forums. This problem needs to be addressed. I'm glad no one walked in front of me when this happened.

- Patterson, LA, USA