We were in the driveway thru lane at a fast food restaurant and all of a sudden the car shut off and the brakes got hard to push in. The car was able to be started at this time but the engine wasn-??t working well. We were able to make it home, slowly and carefully. We had the vehicle towed to a Mechanic and this is what was told to us: Possible increased brake pedal effort due to mechanical engine vacuum pump failure. We had it sent to David's Auto Service 219-861-0666. This could-??ve been a very dangerous accident if we were driving on the expressway or on a regular street going the normal speed limit. Thankfully we were in a drive thru lane.

- Hammond, IN, USA

After driving down around 40 miles, the brakes failed when pulling into a parking spot. There was no indication that the brakes were having issues. No sounds or vibrations were felt. I stopped at a stoplight before turning into the parking lot. Then when attempting to spot in a parking spot, the brakes were very difficult to press. Luckily there was not a vehicle or person in front of me. Had the vehicle taken to a dealer and was told it was the vacuum booster that failed. Upon researching, this has been an issue in past GMC models, but I was told there was no current recall for the vehicle. The vacuum booster was replaced for $540 and I drove the vehicle home. The vehicle showed no issues for the first day. On the second day, I went to pull into a parking spot at a park and the same issue with the brakes occurred. I nearly struck a child that was walking in front of the parking spot. Luckily I was able to slam the pedal to the floor and come to a stop. Took the vehicle to the mechanic and was told the same part had broke. That part has been fixed again and has been fine for 2 days so far. I'm scared that it will happen again and I will not be able to stop in time before I hurt someone else or my family. This needs to be addressed. And I believe I am owed compensation from the manufacturer.

- Argos, IN, USA

Our son and two daughters were driving on the highway at approximately 70mph when a message came up to say the engine was in "Reduced Engine Power". Although nothing seemed to change. The instruction for such and error message is to "get vehicle to a dealership within the next day." So they slowed to 60mph and continued on their way. About 8-10 minutes later another message popped up that said "Service Brake Assist", at which point they immediately tested the brakes and they worked. But 2-5 minutes later they tested the brakes again and the brakes had completely failed! Zero brakes on the highway! No matter how hard the driver pushed the brake pedal there was 0.0% response. So luckily they were able to coast down to about 10 mph with hazard lights on. But at that point they lost everything. No power steering, no engine, and zero brakes. Thank the lord that they were able to have enough room to slow down and get over to a shoulder prior to the loss of power steering and that they had enough room to coast to a stop. Please help, as we were extraordinarily lucky that day that 3 of our children were able to walk away from such a catastrophic vehicle failure. I just do not want that to happen to anyone else.

- Grosse Pointe, MI, USA

Brakes quit working after service light came on. Vehicle will not stop

- Roann, IN, USA

I have been notified that my brake vacuum pump EXPLODED in to my engine, leaving me with limited braking ability. I was driving through a school zone when the brakes went out, I noticed as I was not able to stop at an intersection. This could have led to multiple injuries, including children being in harms way. I had no warning this was coming and now look towards a hefty repair bill. GMC has recalled vacuum pumps in other models but for some reason the terrain is not included. I wonder if there just haven't been enough deaths caused by faulty brake systems for them to cover this model too.

- Jefferson, GA, USA

GMC Corporate Office General Motors Company300 Renaissance Center Detroit, MI 48265 To Whom it May Concern, Been a customer with GMC for a good while despite the issues and troubles we were still loyal to the company. October 31,2021 Sunday, I had sudden lost of my brakes/stalled on my 2019 Terrain SLE while driving to the store close to my area on top of that having less than 30,000 miles in it. Despite the horrible and devastating event I was able to have the truck without any scratch, hit, or had any accident on this event but instead still safely stopped the car down a hill from where I lost my brakes/stalled. Fast forward Nov 2nd had the truck towed to the Milea Pontiac Buick GMC Service And Parts at 3281 E. Tremont Bronx New York 10461. Towing company both from picking up the truck and dropping off Milea had a hard time since the truck was not starting or even able to be placed in neutral to be able to have the truck roll of the flatbed. Nov 2nd Tuesday 2019 GMC Terrain was dropped off at Milea Service and Parts. 1st issue identified by your crew (sort of technical experts) was a bad battery and needs to be replaced, 2nd problem was the computer need to be replaced, 3rd problem was that I had put BAD gas into the tank and the fuel pump need to be replaced after 9 days so fast forward now to Nov 9, 2021.Now finally spoke to a mechanic now stating pistons doesn-??t seem to be firing but does not have proper tools to do the test is trying to get from another dealer to be able to diagnose the problem. Nov 20, 2021, still no news as to what is the real issue on the truck we again visited the Milea to find out what is the deal and still without a truck from Nov 2nd to Nov 20 still yours truly has no loaner and no written nor verbal confirmation of what really cause my lost of my brakes/stalled truck. Linda Cuomo the Milea representative has nothing to inform us regarding the cause and instead waiting for a specialist from out of town which claims to be the e

- Buchanan, NY, USA

I received a "service brake assist" message which came on then off. Took the car to a local mechanic who looked it over and said to see dealer as they saw nothing obvious. internet search revealed that many people with terrain said this warning came on when battery was low. Made a service appt for NJ dealer for 12/6/21. on 12/3/21, began a 1200 mile drive from Florida to NJ, after 2 hours, check engine light came on. Took the exit ramp from I 75 and at end of ramp, there was a total braking failure. I had to press very hard to eventually stop. Shut off car, attempted to restart but it would not. Towed to a mechanic who found fluid leakage and a repair bulletin on GM site involving vacuum seal camshaft. #pip5598A diagnostic tip. Internet search reveals many anecdotal instances of same problem. On Monday, 12/6/21, I received an email from GMAC saying that the on board diagnostics had shown a "low battery" concern. The catastrophic loss of braking seems to be connected to a low battery situation. This needs to be looked into by NHTSA.

- Long Branch, NJ, USA

Driving down load. Brake pedal got stiff as a rock. Brakes started to lock up. Almost caused a collision, as the car would not stop

- Derby , KS, USA