Which parts fail
Components named in complaints (service brakes, ABS, rotors and pads, parking brake).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2010 Mazda CX-9 owners, lightly cleaned up (personal details are redacted by NHTSA).
While driving the vehicle went to stop car and was unable to stop brake pedal was hard as a rock luckily I didn't hit anything or anyone. upon further research it seems that this model has an issues with the brake booster failing causing exactly what I experienced. As it turns out I did not qualify for the extended warranty on the brake booster due to a agreement between you and mazda my issue is it should be life of the model with no expiration date due to the fact it can happen at any moment. Luckily my family wasn't harmed and luckily someone else's family wasn't harmed because of this failure. My vehicle only has 86,000+ miles.
Brakes not working due to brake booster problem which was brought to the attention of Mazda. Mazda and the transportation authority agreed on an extended warranty which is no longer in effect. There have been many more complaints for this same problem, yet a recall has not been listed for this vechicle and alot of people are paying out of pocket. I already brought this to the attention of traffic safety and never received a return reply. Brakes are squishy than you end up having to put brakes all the way to get car to stop. People are unaware of this major brake and safety defect
Braking inconsistently - sometimes easy to stop, sometimes hard. I had brakes looked at, and the man said it was the brake booster. He googled it, and found a recall online and told me to take it to my dealer. It doesn't look like there's an active recall - but a lot of complaints. What's going on? This is going to be expensive. My college age daughter drives that car. Do they have to have a severe accident to get that fixed? I can't afford to fix it right now.
The contact owns a 2010 Mazda CX-9. The contact stated that while driving at an undisclosed speed, the vehicle was unable to stop while the brake pedal was depressed. The vehicle was taken to an independent mechanic who was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 162,706. The consumer stated the brake booster was replaced on 07/22/2022.
My wife was taking my daughters for marching band and all of a sudden she tried to press the brakes but the brakes felt too hard and she was unable to stop the car safely. She had to take immediate action by moving the car to the shoulder to stop the car. There were no warning signs on the screen. The car was taken to the mechanic and the dealership. The dealership said that this was a brake booster issue which would be fixed for $1500. This is a serious issue which if had happened on the highway would have been tragic. Mazda and the dealership refuse to fix this free of cost since they say that they had already communicated about "an extension of warranty" to fix this problem in 2015 - at which time there were no issues with the brakes.
Driving and brakes would not work without pressing really hard. The problem was reported before on these cars and continue to be a problem. https://www.carcomplaints.com/Mazda/CX-9/2010/brakes/stiff_difficult_braking.shtml my car has been in 2 shops for about 3 months now. They had to replace several parts in the braking system. Than the rear brakes completely froze up and towed to Mazda out of Greensboro NC.
Driving on I-5, near Gold Hill, Oregon, when the traction control system light came on and the Vehicle slowed down. I had to push the gas pedal to the floor to get the car to move and I could not shift gears! It shuddered and the wheels seemed to lock up. I could smell burning rubber. I forced the car to the next exit, pulled off and shut it down. I sat there waiting for it to cool off. When I started it again it was a little rough at first but then seemed to get better and I was able to get home. I bought the car in June of 2020 from Lithia Motors in Medford, Oregon. I also bought a Power Train Warranty For $2,500 which was set to expire on 6/10/2021. I called Lithia and made an appointment to take it to them for repairs on June 1, 2021. I got as far as Grants Pass, OR, and it did the same thing I described above. I called a tow truck and had it towed to Lithia in Medford. …
Vehicles brakes suddenly stopped working causing a low speed collision. I had the brakes inspected, and was told this was a known issue with my car, but Mazda did not initiate a recall. I then discovered that the NHTSA had struck a deal with Mazda, agreeing to an extended warranty with no customer notification. This is a clear case of a government agency that is supposed to protect consumers, shirking their duty. NHTSA and Mazda you should be ashamed of yourselves!
2010-11 CX-9 brake booster failure. Rapid onset from first symptoms to complete failure braking occurred within 45 minutes of driving on heavy interstate congested traffic during rush hour. Breaking failure is most significant if breaking is first applied lightly as a cautionary measure. Applying light breaks results in breaking system pressure to rapidly drop disabling assisted breaking within a few seconds. Breaking a heavy vehicle with fail power assist almost always resulted in either insufficient braking, or wheel lockup. (note, ABS fails). The assist braking then returns if brake is release for more than 10 seconds providing the brake is not applied. This is a significant safety hazard that May easily result in the destruction of property and death. The defect seems to have been glossed over by the NHTSA in April 2014 when the NHTSA investigation into this failure was closed. …
Took my car to dealer 2-3 times for the brakes, way before my warranty was any where near expiring, because I kept hearing a grinding sound. They kept telling me nothing was wrong, that my brakes had some gravel on them and they just cleaned them. I don't travel on dirt roads or anything, city roads/highways. No out of town travel at all, actual only in town travel, home/work. My 2nd concern is, while driving sometimes my speed seems to shift, as if the gears are shifting. 3rd concern is, I received a recall notice, don't recall what it was about but I took it to the dealership and I was told they done that work last time I came in but I don't believe it was done, since they haven't been honest with me before. They didn't even look at the letter. If I recall correctly brake complaints/ service started 2011 or 2012 to 2014....
NHTSA investigations
Brake Booster Failure
In March 2014, Mazda Motor Corporation (Mazda) initiated Special Service Program SSP93 to extend the warranty coverage for a specific brake booster fault condition on model year (MY) 2007-2013 Mazda CX-9 vehicles.According to Mazda's dealer communication for SSP93, the subject vehicles may exhibit a condition were the brake pedal is harder than usual to depress.
Brake complaints in other CX-9 years
Frequently asked questions
How common are brake problems on the 2010 Mazda CX-9?
NHTSA has 76 complaints about the brakes of the 2010 Mazda CX-9, 47% of the model year's 162 complaints. The component named most often is pedals and linkages (1 mentions).
Is there a recall for 2010 Mazda CX-9 brake problems?
No. NHTSA lists no brakes recall for the 2010 Mazda CX-9, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2010 Mazda CX-9 brake problems start?
Half of the complaints with a recorded mileage happened before about 75,000 miles, and 3% before 25,000 miles.
Is it dangerous?
Owners linked 5 crashes, 0 fires and 2 injuries to brakes problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.