Two problems related to brakes failed have been reported for the 2009 Mazda CX9. The most recently reported issues are listed below.
Hissing sound when brake pedal is pressed. Pedal gets really hard to push then it goes to the floor when attempting to stop the vehicle. In a panic stop it feels that the car will not be able to stop. I am told that the brake booster has failed. The mileage on the vehicle is approximately 138,000 miles.
The contact owns a 2009 Mazda cx-9. While approaching a stop light in order to make a right turn, the brakes failed to stop the vehicle when the pedal was depressed. The contact had to continue to drive into a nearby parking lot until the vehicle came to a stop. The contact turned off the vehicle and had it towed to a certified mechanic. The mechanic diagnosed that the power brake booster needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 80,000.