The break booster went out without any warning or indicators while driving almost resulting in a collision. There are no warning lights on the dashboard.
2010 Mazda CX-9 brakes problems
91 complaints (47% of all complaints for this car). Typical mileage when it fails: 85,000. 5 crashes reported.
- owner complaints
- 91
- of this car's complaints
- 47%
- typical mileage
- 85,000
- crashes
- 5
- recalls
- 0
Which part fails
- Pedals and linkages1
At what mileage
Complaints by mileage at the time of the problem.
0k-25k
25k-50k
50k-75k
75k-100k
100k-125k
125k-150k
150k-175k
175k-200k
200k+
Mazda CX-9 brakes problems in other years
Specific symptoms reported on the 2010 Mazda CX-9 brakes
Phrases found in the owners' own descriptions, so one complaint can mention several symptoms.
Related recalls
No recalls on record for this model year.
Related 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. Complainants report hearing air leakage (hissing) from the driver-side foot area during braking.The Mazda program extends the warranty coverage for repairing this condition to unlimited time and mileage for repairs performed between March 31, 2014 and March 31, 2015 and to 7 years or 90,000 miles for repairs performed after March 31, 2015.In its response to the Office of Defects Investigation's (ODI) information request letter for PE14-005, Mazda identified a problem with booster diaphragms developing tears near the outer seal/circumference that can result in noise and degraded booster performance as the tears grow in length (Figures 1-3).The tears allow leakage from the ambient to the vacuum sides of the diaphragm that reduces the differential pressure across the diaphragm and produces a hissing noise after the tears have reached 10-12 mm in length.The problem was caused by wear of the mold used for the diaphragm forming process, which resulted in increased thickness and stress in the bending area of the diaphragm.Continuous operation in environments with high ambient temperatures accelerates the hardening of the diaphragm material, further increasing the stress in the bending area and contributing to tear initiation and propagation rate.Analysis of failure data indicates that the tool wear condition affected vehicles produced after June 2010 and operated in hot states (Figures 4-6).In February 2013 the supplier introduced a new mold and changes to the diaphragm thickness monitoring process to correct the condition in production vehicles.Analysis of complaint and supplier test data indicates that the diaphragm tear condition is a progressive failure that develops slowly over time.Smaller tears have little effect on system performance.As the tear continues to grow, the effects become more evident.The hard pedal and increased effort are experienced during initial pedal application, but are diminished as the pedal is pressed further by the driver and the tear is partially sealed by the outer wall of the booster.This change from a hard to a soft pedal feel is described by some drivers as a spongy pedal.For tear lengths that were observed in warranty return parts, testing demonstrated that most booster performance can be recovered with increasing pedal apply speed and apply force.None of the tears measured in return parts grew large enough to cause a complete loss of brake booster function. The booster diaphragm tear condition results in partial reduction in booster function that progresses gradually over time with audible and pedal feel symptoms available to the driver.The condition does not result in a sudden loss of power braking assist.The effects are evident during initial pedal apply and are reduced by increased pedal apply force and rate.ODI has not identified any accidents associated with the booster diaphragm tear condition in the subject vehicles.Accordingly, this investigation is closed.The closing of this investigation does not constitute a finding by the federal safety agency that a safety-related defect does not exist.The agency will continue to monitor complaints and other information relating to the alleged defect and take further action in the future if warranted.VOQs (24) associated with this investigation:10482005, 10486941, 1048793
PE14005
What 2010 Mazda CX-9 owners say
Most recent owner complaints, unedited.
Stiff brake pedal , more effort to stop and longer distant to stop.
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.
Vehicle difficult to stop, believe it is a bad brake booster.
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.
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
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.
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.
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.
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. When I got to Medford, the Service Manager told me I would have to take it to Crater Lake Ford. When I got to Crater Lake Ford I was told to take it to Crater Lake Mazda which I did. I described in detail what the car was doing to.the Service.Manager and told him I feared it was some kind of transmission problem. I also told him I had a power Train. Warranty the would expire on June10thso time was no the essence! I never suspected the brakes because we had the bakes repaired in November of 2020 at Lithia Motors. They were making a hissing sound. They replaced the.brake booster among other brake parts for $1,300 plus. That job was still under warranty. I got a call on June 15th telling me the problem was in the gear shift. He said it was now repaired and I could come and pick it up. I paid $674 for that repair. I got three miles from the dealership and the original problem occurred. I had it towed back to Mazda and it has been there ever since!! They replaced they're (traction control module), but that didn't fix it. After test driving it the original problem occurred! It's still at Mazda.
Questions about the 2010 Mazda CX-9 brakes
Does the 2010 Mazda CX-9 have brakes problems?
Owners have filed 91 complaints about the brakes of the 2010 Mazda CX-9, 47% of all its complaints, more than any other problem.
At what mileage do 2010 Mazda CX-9 brakes problems start?
The typical (median) mileage in owner complaints is 85,000 miles.
Was there a recall on the 2010 Mazda CX-9 brakes?
There is no recall for this problem on this model year.
What year does the Mazda CX-9 have bad brakes?
The Mazda CX-9 model years with the most brakes complaints are 2012 (143 complaints), 2011 (99 complaints) and 2010 (91 complaints).
Other 2010 Mazda CX-9 problems
Engine 27Transmission 23Airbags 18Suspension 16Acceleration 9Body 6Electrical 6Lights 4Steering 4Wheels 4Driver assistance 3Seats 3Fuel system 2Visibility 2Locks 1Seat belts 1Tires 1
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