Brake booster failure. The power assisted braking has stopped working. There are no leaking vacuum hoses and the check valve is working. The brake pedal travels to the floorboard.
2011 Mazda CX-9 brakes problems
99 complaints (58% of all complaints for this car). Typical mileage when it fails: 72,246. 4 crashes reported.
- owner complaints
- 99
- of this car's complaints
- 58%
- typical mileage
- 72,246
- crashes
- 4
- recalls
- 0
Which part fails
- Power assist: vacuum1
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 2011 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 2011 Mazda CX-9 owners say
Most recent owner complaints, unedited.
The contact owns a 2011 Mazda CX-9. The contact stated while driving 20 MPH, there was an abnormal sound coming from the brakes. The contact stated that the brake pedal was firm and difficult to depress while attempting to stop the vehicle. The vehicle was not diagnosed or repaired. The manufacturer was contacted, and a case was filed. The failure mileage was 67,000.
Braking trouble recent in weeks in 2011 Mazda CX-9 vehicle. Had mechanic (Euro Motorsports in Chagrin Falls OH) check it out. Turned out to be a faulty Brake Booster. Mechanic test drove car; braking failed and he almost rear-ended another vehicle. He found on line a Mazda service notice dating from April 4, 2014 called SSP93. Mazda issued an extended warranty of 7 years or 90,000 miles, whichever came first, to have defective part replaced by an improved part. But we were never informed by Mazda of Bedford, where we bought the vehicle. Currently, our vehicle has about 83,000 miles. Never knew there was a problem until recent trouble with the braking. There are thousands of CX-5, Cx-7, and Cx-9 vehicles in operation in U.S. right now; probably many owners have no idea there is a brake defect in their vehicles that could cause a serious accident, potentially fatal. Mazda should have done a recall in 2014, not an extended warranty. Although Brake Boosters are supposedly good for at least 150,000 miles of driving, our brake failure at around 83,000 miles proves otherwise. the federal safety agency should order Mazda to recall all vehicles with the defective brake part and replace them at Mazda's expense, probably hundreds of dollars each time. We do not want to have our brake booster replaced by our regular Euro Motosports mechanics because a recall must typically be repaired by the dealer. We already filed a complaint with State of Ohio Attorney General's office, but their people say the complaint must first go through BBB. No urgency on their part at all, even when informed potentially fatal flaw in the brakes. To avoid dangerous accidents, the federal safety agency should act more swiftly. Thanks.
Sirt: I purchased my 2011 mazda cx 9 from my close friend [xxx] on dec.05 of 2014! [xxx] had not been issued a special services program about the brake booster! Well I never received this info either? In fact I had two recall that were taken care of by the local mazda dealer here in thousand oaks calif. This known brake booster detonation has been known by mazda.iot is a very dangerous condition and is not to safe to drive the car at all- I will not drive the car and seethe original matter should have been let it be known to myself and feel the matter should be addressed asap by mazda -thank you [xxx] adding backing -very hard brake - when driving it had to really stand hard on the brake to stop car b! All indications point to a brake booster failure ! To summarize io was never notified by mazda about the special service program for the repair of this extremely unsafe brake problem! Information redacted pursuant to the freedom of information act (foia), 5 u.s.c. 552(b)(6).
The brake pedal seems hard too stop the car when in motion on public streets, vehicle continues too roll upon pumping brakes, have too continuously pump the brake hard too stop the vehicle, had the front brakes replaced recently, and brake pedal is still not functioning correctly, possibly the brake booster.
I went from having brakes to having to push the brake to the floor, which still did not stop the car, all in the same day. I was lucky not to wreck but could not stop for stop signs or stop lights all while my 22 month old was in the vehicle. Something in the brake system messed up, and it still had a full thing of brake fluid. I believe that it is the brake booster causing this problem.
Brakes when applied would sometimes go to the floor before stopping. The brake booster has gone bad and very dangerous almost causing an accident. Brake pedal soft and sometimes will not stop.
Brakes really hard to press. Wife thought car wasn't going to stop and she was going to rear end car in front of her. Sometimes brake pedal would feel spongy. Over last month there was an intermittent strange noise sometimes when car was started. Mazda dealership identified the problem to be a defective brake booster. I found that the federal safety agency opened investigation on cx-9 brake issues previously and mazda identified problem to be brake booster. Mazda extended the warranty to 7 years or 90,000 miles and the federal safety agency closed investigation. Our brake booster failed at 9 years with 79,388 miles on the car. From what I have read the life expectancy of a brake booster is the life of the car. Mazda never informed us about this possible problem. Our family could have been seriously injured or killed due to this defect. Why did the federal safety agency accept an extended warranty as a solution?
Tl* the contact owns a 2011 mazda cx9. The contact stated that while his wife was driving approximately 13 MPH and attempting to slow down, the brake pedal was harder than usual to depress. As a result, the driver rear ended the vehicle in front causing a five vehicle collision at a traffic light. None of the frontal air bags deployed. The police were present and a police report was filed. There were no injuries reported. The vehicle was towed to an impound lot where the insurance company was scheduled to have an inspector inspect the vehicle. The vehicle was not taken to the dealer for a diagnostic. The vehicle was not repaired. The manufacturer was not notified of the failure. The contact referenced the federal safety agency action number: pe14005 (service brakes, hydraulic). The VIN was not available. The approximate failure mileage was 86,000.
Brake booster is leaking. Takes longer to stop. Called mazda and reported issue.
Questions about the 2011 Mazda CX-9 brakes
Does the 2011 Mazda CX-9 have brakes problems?
Owners have filed 99 complaints about the brakes of the 2011 Mazda CX-9, 58% of all its complaints, more than any other problem.
At what mileage do 2011 Mazda CX-9 brakes problems start?
The typical (median) mileage in owner complaints is 72,246 miles.
Was there a recall on the 2011 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 2011 Mazda CX-9 problems
Transmission 25Airbags 22Engine 15Suspension 8Electrical 6Driver assistance 5Acceleration 4Steering 4Lights 3Wheels 3Seat belts 2Body 1Fuel system 1Seats 1Tires 1Visibility 1
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