Service Brakes Problems of GMC Terrain - part 2

I was driving my morning commute to work, when I came upon a stop light. I was pressing the brakes and the brakes failed to engage which caused me to hit a car in front of me. I did not have any warnings that the brakes were defective. The warning on the dash did not indicate that there was anything wrong with brakes. I had my set belt, was going the speed limit and my brakes just gave out. I have injury’s to my arms, shoulder, neck, and head. The other vehicle driver was not hurt. Thank the lord.

See all problems of the 2016 GMC Terrain 🔎.

Two weeks ago I was driving on the highway. My car felt fine. No warning light the dashboard. Suddenly I receive a notification on my dash stating “engine speed reduced” and my check engine light went on. My car at this point still feels fine, not shaking, no smoke, etc. I’m on the highway and not in a safe position to pull over. 2 minutes later I receive another notification on my dash stating “service breaks”. I immediately tap my brakes to check and they are stiff. I let off the gas as I was approaching the exit and begin pumping my brakes. They continue to be stiff. Luckily there was no one I front of me as this exit led to a rotary. I was able to coast around the rotary and into a parking lot where I attempted to push the e- break which did not work. My steering tightened and then my car died. I have the car towed to GMC where I bought the vehicle. Am told I will be charged a diagnostic fee and they will let me know what they find before repairs are made. I receive a call back the following day stating “the vacuum pump exploded causing you to loose brakes”. I was told “the vacuum pump and repairs would be about $1,200. But they could not guarantee that once the vacuum pump was removed, there wouldn’t be more debris and destruction to the cam shaft and engine”. We asked they continue with the diagnostics and check the engine for debris. We receive a call back stating “the vacuum pump exploded and there are shards of medal debris in your engine”. Recommendations are that I need a new engine as "the vacuum pump explosion caused catastrophic damage to the engine". My safety and the safety of other innocent drivers on the highway were put in extreme danger! I lost all break control, power steering, and emergency break control. I had minutes from the time the first warning alerted to the time I lost complete control of the car. This is a known issue with gm motors specifically made between 2016-2019.

See all problems of the 2019 GMC Terrain 🔎.

While driving the vehicle the car went into limp mode and the back brakes stopped working. The car had to be drifted into a parking lot. The vacuum pump malfunctioned and has damaged the engine. If it was me in the driver seat instead of my partner, the incident would’ve 100% been an accident. The car was really unable to be controlled and we just happened to have that space that was empty to turn into. The car gave code when this happened. When getting a tow the car also wouldn’t take itself out of park or start to go into neutral to move the car to get it towed. Nothing is working with each other anymore and we were on a busy road of people when our brakes just went out.

Driving down busy highway and suddenly had no brakes!!! no lights came on dashboard as a warning. Found out it was a braking pump that broke and shot metal pieces into the engine. Now im facing a new engine for a 2020 Terrain!!.

See all problems of the 2020 GMC Terrain 🔎.

I was driving on the expressway, attempted to brake and the brakes were stiff and would not go down to stop the vehicle. . Thankfully, I was able to glide over three lanes of traffic and exit the expressway and glide into a parking lot and drove around until the car came to a stop. No lights. No warning. The car had to be towed to my mechanic. This could have been catastrophic. I could have killed someone else or myself. This is the second time that this has happened with this vehicle!!! by the grace of god I am still here writing this complaint. I am traumatized and do not feel safe driving this car. They must recall this vehicle before somebody gets killed. The issue is with the vacuum pump and I have seen other complaints about the same issue.

Master cylinder , less then 1000 miles was pulling out of a parking lot and the brakes went out.

As I was driving down the ohio turnpike on my way to work on Tuesday, August 5, 2025, my check engine light came on. Almost immediately I got a notification that the car was operating at reduced power. I had no previous issues with the vehicle. As I got off the turnpike my braking system failed. I was able to come to a stop partially in the grass before entering into oncoming traffic. The entire car shut down. I was unable to restart the car. We were also unable to put the car into neutral to push it off of the road the remainder of the way because the wheels were completely locked up at this point. The parking brake was engaged on its own. We also could not get the car into neutral. I had the car towed to a local repair shop, not knowing at all what the issue was. The vacuum pump had failed and broke apart in the engine. This caused my braking system to fail completely also. The vacuum pump on my 2020 GMC Terrain has been noted as faulty or defective. However, an official recall has not been issued for my vehicle. Had the pump failed a moment sooner I could have been in a crash trying to exit the turnpike. I took my vehicle to a repair shop and spent $1400 out-of-pocket. The car still does not run correctly now as there are pieces in the engine of my vehicle that were unable to be retrieved.

Friday July 25, 2025 I was driving my 2019 GMC Terrain sle and when exiting the interstate the brake pedal got hard and I could not stop. After almost rear ending another vehicle, I got the vehicle into the ditch and safely off the road. After several attempts to correct the problem, I was unsuccessful. The vehicle was towed home and seen by a mechanic. The vacuum pump went out while I was driving.

While working out of town for work my engine light started flashing and the dash lights went nuts. My brakes were nonexistent and were hard as a rock. I had zero warning as to what happened. Working 3 hours away from home the car had to be towed and I was informed the engine code came back as my cam shaft. Took it to the dealer as gm has a bulletin put out. I didn’t know what that meant. Long story short and 3000. 00 dollars later I find out that the vacuum pump exploded which cause the cam shaft to fail. I was out of work for almost a month. There is a recall for almost all vehicles from this year but not the 2019 Terrain even though it contains the same vacuum pump as all the recalled makes and models. Vacuum pump, cam shaft, oil pan, oil pump had to all be replaced at under 100,000 highway miles. Someone needs to address this problem.

Difficulty with power assistive braking when traveling at low speeds.

See all problems of the 2018 GMC Terrain 🔎.

Component affected: service brakes, hydraulic – brake vacuum pump summary of the problem: I am reporting a serious safety issue involving the brake vacuum pump on my 2018 GMC Terrain. The brake pump failed catastrophically ("blew up"), resulting in a sudden loss of braking power. This occurred without warning and posed a significant risk to my safety and others on the road. We were traveling to vacation in florida and thankfully had just gotten off the interstate. Details: the failure caused the brake pedal to become extremely hard to press, and the vehicle required a much longer distance to stop. We experienced no brake at the brake booster and a blown vacuum pump is due to a faulty vacuum pump which is a known issue for this model. Fortunately, no accident occurred, but the situation could have easily led to a collision. A certified mechanic confirmed that the brake vacuum pump exploded and needs to be replaced. I have incurred significant out-of-pocket repair costs due to this issue. We had to uber to our vacation room, get walmart plus to have groceries delivered to our room. We had to have uber eats deliver other supplies. We have had to walk to various places for dinner and entertainment because avis and budget had no vehicles available to rent and enterprise was closed as we arrived on Saturday afternoon. I have checked for recalls and service bulletins using my VIN, but none are currently listed for this specific issue, despite similar problems being reported in other gm vehicles. Request: I urge the NHTSA to investigate this issue further. The failure of a critical braking component without warning is a serious safety concern. I believe this may be part of a broader pattern of brake system failures in gm vehicles and should be addressed through a recall or safety campaign. Also, the estimate for the repair is $2,500 so any reimbursement would be greatly appreciated. We just received this estimate but I can provide it at a later date.

I was driving on the highway & my brakes failed. My brake pedal was completely hard & could not be used. I had to steer onto an exit ramp & be towed to the dealership. There was absolutely no warning of this happening. Once at the dealership, they confirmed it was my vacuum pump that blew up, which damaged the camshaft & caused pieces of metal to be floating around in my engine. The greater portion of the repair was covered under warranty, however, I had to pay $350 out of pocket. This could have been catastrophic. I or others on the road could have been injure for worse. This system failure should be fixed immediately and owners be compensated. I do not feel safe driving myself or my family in this vehicle after experiencing this occurrence.

The contact owns a 2021 GMC Terrain. The contact stated that the transmission was previously replaced. The contact stated that upon starting the vehicle, the check engine warning light illuminated. The failure had occurred intermittently. Additionally, the contact stated that while driving approximately 15-20 mph and depressing the accelerator pedal, the vehicle failed to respond for approximately 1 minute. The vehicle was taken to the Nissan dealer it was purchased several times. The dealer retrieved diagnostic trouble codes: p057c and p057e, and the brake pedal position sensor was replaced twice; however, the failure persisted. The Nissan dealer took the vehicle to a gm dealer, where the cause of the failure could not be determined. The vehicle was not repaired. The contact related the failure to TSB number: pit5994 (diagnostic tip for reduced or low engine power on acceleration). The manufacturer was notified of the failure and referred the contact to the NHTSA hotline for assistance. The failure mileage was approximately 78,843.

See all problems of the 2021 GMC Terrain 🔎.

My car started experiencing a strange problem while braking on June 15. I released the parking brake leaving my parents driveway. I coasted backwards (as usual), and when I pressed the brake the car didn't stop as expected and the brake pedal was very hard to press. It eventually stopped. I put into park, then put the emergency brake on, then released all and tried again and encountered the same issue, that it was very very slow to stop and the brake pedal was hard to push in. I got home, parked the car - tested the reverse brake on flat surface and didn't notice the issue. The next day, the problem started happening with the front brake as well and an error code popped up that said 'check brake assist' which I've never seen before. I brought it to my local mechanic, who took a look and said that it's a vacuum pump failure, and the result is a lot of metal shards were released into the engine when the vacuum pump failed. My mechanic recommended I take to a GMC dealer for further evaluation. I looked up the recall on this issue, and see that it impacts a lot cars, including the 2017 GMC Terrain, but not my 2018 GMC Terrain. I am going to take it to the GMC dealer but I'm afraid I won't be able to afford the repair, and it doesn't seem like there was anything I could have done to prevent this from happening.

I got off a highway exit ramp and with no warning my brakes were hard to press. There was no warning lights on my dash. The brakes take a lot of force to push for a stop. The warning light finally came on a day later with codes p0556 and u040171.

The contact's wife owns a 2019 GMC Terrain. The contact stated while driving 70 mph and depressing the brake pedal, the brake pedal was firm, and the vehicle failed to respond as needed. The check engine warning light was illuminated. The contact stated that upon depressing the brake pedal with excessive force, the vehicle responded as needed. The contact stated upon inspecting underneath the brake booster, the contact noticed a lot of debris due to lack of vacuum pressure. The dealer and the manufacturer were notified of the failure and referred the contact to the NHTSA hotline to report the failure. The vehicle was not diagnosed or repaired. The failure mileage was approximately 80,000.

On Monday 5/26/2025 I was on the way home from work, coming down my street to turn in my drive (at approximately 2130) I pushed on the brake getting ready to make my turn, my car would not stop. It traveled maybe 100 -200 feet before coming to a stop. The brake pedal would not push in. (as I live on a cul-DE-sac, if this happened during the daylight, there would have been children playing in the street and I could have killed someone's child). I managed very slowly to reverse the car and finally get it in the driveway. I thought it was going to hit my house!! upon reading a lot of issues and complaints on my vehicle make/model I pretty much figured it was the brake vacuum pump. I called gm, however my car has 74,000 miles, is out of warranty and no recalls for my VIN so I'm told I have to have it fixed. My neighbor is a certified mechanic and has a shop. He looked at it and confirmed it is the vac pump. Not only that but the end that goes into the motor has sheared off and not there is metal pieces and fragments in my motor. I had to have it towed to his shop. (this morning) as of right now I am waiting to see if the motor can be flushed or if I am going to end up having to replace motor. I have missed several days of work due to transportation and now have to rent a car, and pay who knows how much for repairs which could easily cost thousands. I live week to week and still make payments on this car!! this is a faulty part and should have been a recall as I have read on many many complaints of bad brake vacuum pump on the GMC Terrains even the 2020 models and up. Some of the others are already recalled but not mine. In the photos, on one you can see the big chunk of metal. On another where the piece came of of motor you can see where metal was scraping the camshaft in the motor and very small metal fragments around the opening.

Vacuum pump broke and car has no brakes.

The contact owns a 2025 GMC Terrain. The contact stated that while his wife was driving approximately 40 mph on wet roads, the brake pedal was depressed, but the brake pedal was stiff, preventing the vehicle from slowing down as intended. There were several unknown warning lights illuminated during the failure. The accelerator pedal was released, and the vehicle rolled to a stop. The vehicle was turned off and restarted, but the check engine warning light remained illuminated. The vehicle was pulled over to the side of the road and turned off. The vehicle was then towed to a dealer, where it was diagnosed, and determined that the brake control module needed to be replaced. The vehicle was repaired, but the failure reoccurred approximately 7 months and 2 weeks later. The manufacturer was notified of the failure. The failure mileage was approximately 1,126.

See all problems of the 2025 GMC Terrain 🔎.

Abs brake problem and have tried to get it repaired for over 3 months and cannot seem to be able to get the part and call gm with no help. Can not tell me when or where to buy the part. Nobody seems to be able to get a new part and no help from gm. If there is this many problems that there is no part left available it should be a national recall.

See all problems of the 2014 GMC Terrain 🔎.

While driving the breaks completely locked up and the smell of exhaust entered through vents. Ran a code machine indicating that the break booster power vacuum pump was needing replaced. There are no other issues with my vehicle that would cause it to malfunction out of no where.

Breaks went out on vehicle with no warning or lights on dash. Nothing prior or now indicating any issues with breaking system.

Brake booster went out and lost all braking ability on interstate doing 65 mph in spring of 2022 - had brake booster and exhaust cam replaced and April 20 2025 same break and same effect - no braking ability at interstate speed - extremely dangerous situation.

The contact owns a 2024 GMC Terrain. The contact stated that while driving at various speeds, the vehicle was hesitating while accelerating. The contact stated that the vehicle was stalling, and the brake pedal was spongy. The vehicle was taken to the local dealer on several occasions, but the failure was not duplicated. The vehicle was not repaired. The contact stated that the failure persisted. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was 10.

See all problems of the 2024 GMC Terrain 🔎.

Brake vacuum pump premature failure. As you see GMC, Terrains, in equinox, I have an issue, while the engine it's on while driving etc, if this bark fails, you will have an issue I'm trying to stop. This is a known problem or gm. And as of now, they have not come out with a solution or a recall for this problem. This problem has caused many customers. To lose thousands of dollars, he repairs. I'm not covered by the warranty. This should be addressed and repaired as soon as possible as it may cause someone else to lose their life. Second problem is the 9 speed transmission transmission lack power when trying to gain speed as you enter the highway. Lastly they blamed the selenoids etc. Lastly the pulley belt retention broke down premature with only 68k miles. This is an ongoing problem gm is well aware and tries to hide or fix. When someone buys a vehicle we expect to last longer than 100k miles.

My SUV pulls hard to the right when braking at speeds above 50 mph and much more on the interstates at 65 mph and above. I first experienced this after three weeks of ownership on a drive up I-95 on a trip to nc. It has happened numerous times while traveling on the interstates and has almost caused loss of control when having to brake hard when cut off by another driver or traffic suddenly coming to a stop. The vehicle has been to the service department numerous times. . . . At first they suspected a braking issue and have had both calipers replaced, all brake lines replaced, lower control arms replaced and the right side strut replaced. None of these repairs have solved the problem. The factory service rep who took over the situation tested 3 other GMC 2025 Terrain suvs and all had the same problem. He reported the issue on a safety report to gm in michigan and the response from gm was that it is a normal condition for the Terrain models. I have never owned, driven, or ridden in another vehicle in over 50 years of driving which performed like this, this is not a normal condition in my opinion.

Service brake assist came on, check engine light came on and vehicle was hard to stop. Took to authorized service dealer and all parts were replaced. After driving it for a little while, service brake assist back on, check engine light back on and vehilce is hard to stop.

The contact owns a 2020 GMC Terrain. The contact stated that while driving at slow speeds in a parking area and attempting to stop, the brake pedal failed to depress all the way to the floorboard and was firm, requiring an increased effort; however, the vehicle failed to stop as intended. The contact was able to bring the vehicle to a complete stop by turning the vehicle off. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the brake vacuum pump, observing that the pump had sent metal fragments into the engine, resulting in damages to the engine. The vehicle was not repaired. After investigating the failure, the contact related the failure to special coverage adjustment: n182202780. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 108,000. The VIN was not available.

Vacuum pump failed causing hard brake pedal and the inability to properly stop the vehicle. Thankfully I made it to a safe area and had the vehicle towed. No warning light or engine service lights ever illuminated. Once it was taken apart the bearings were disintegrated and metal shavings are in engine components.

Brakes stopped working while driving. Yes it has been reproduced by mechanic. No it has not been inspected by manufacturer. “service brake assist” message populated after failure.

Service parking brake comes on, steering reduced. Problem reoccurring often, but intermittently. Actuators malfunctioning causing many sensors to fail off and on. Huge safety concern for myself, my riders, and anyone else on the road. When this happens my car has to “think” to move unless you clear the pop up message. Check engine light comes off and on at its leisure. When steering reduced comes on the car will not move until ready. This is clearly affecting electrical things as when I shut power off to other supplies it sometimes becomes more frequent as well as less frequent. The car does not understand what to do as its computers are confused at what the problem is, as the problem does not consistently happen. I have print outs of one time I caught it with failing actuators. I refuse to go to the dealership as I’m told “OH the problem isn’t happening now. ” which negates safety of all people on the roadways. You’re more than welcome to inspect. Though I will be present as I refuse to be told there’s no problem. As previously stated this happens when it wants to happen, but again I’ve caught the issue and can supply information.

I was slowing down to turn and I couldn't push my brake pedal down it completely locked up. If I wasn't already slowing down I would've hit a power pole and potentially lost my life. My abs light never came on and it's still not on. After I got parked and shut my car off the check engine light came on.

Driving home from dropping my daughter off at school. When slowing down at stop sign, car locked up brakes completely, almost went through stop sign, car shut down engine and placed vehicle in park. Diagnosis is a vacuum pump failure, causing reluctor wheel to spin freely from camshaft. This happened without warning at 70k miles. Diagnostic report from three weeks prior showed no bad diagnostics with engine or drivetrain components, or brake components. Had to have car towed from intersection where I was impeding traffic due to sudden failure. Garage is concerned regarding potential for debris and engine damage, as well as timing issues due to sudden failure of vacuum pump. Gm has authorized vacuum pump recalls on other makes from prior years, not Terrain for some reason. This is how becoming highly reported failure among GMC/chevy vehicles with shaft driven vacuum pump design between 2019-2022. Gm has stopped using this design on 23 and newer models. They should absolutely recall these older models for this issue. Sudden vacuum pump failure can lead to unrepairable engine damage due to design.

The contact owns a 2020 GMC Terrain. The contact stated that the vehicle failed to stop while driving 55 mph while depressing the brake pedal. The contact pressed the button that immediately shifted the transmission to park, and the vehicle came to a stop. The contact drove the vehicle to a safe parking space. After safely parking the vehicle off-road, the check engine and brake assist warning lights illuminated. The vehicle was towed to the dealer who diagnosed that the brake booster pump and camshaft had fractured and detached from the vehicle. The contact was informed that the brake booster, vacuum pump, and camshaft needed to be replaced. The vehicle was not repaired because the dealer was awaiting the parts to repair the vehicle. The manufacturer was not informed of the failure. The failure mileage was 101,700.

My vacuum pump went out. My brakes went out at 86k miles. Very pour design.