brake booster failure?

Is this an example of a brake booster failure ? Seems like the guy lost the brakes when he started downhill (there was an unusual sound as he went downhill) he left his foot on the brakes (he's saying: "I can't control it!! I can't control it!!") until he realized in the last seconds to release his foot and press down hard and pump the brakes repeatedly before he smashed into the parked cars there was some sort of hissing sound at the end like brake booster failure. Obvious this isn't a 2016 model, video was shot in 2014, there's a TSB out for the brake booster but no recall?? seems like a dangerous situation, guy was lucky it was a garage and not during a downhill highway emergency stop situation.

If this person lost control of the brakes and the location happens to be here in the u.s. why doesn't he report it to the NHTSA. I hope that is the correct spelling. It looks like though this took place in china? anyway this should be a recall not a tsb as someone can get killed if this happened on the highway or a steep hill into traffic.

kornholio said:

If this person lost control of the brakes and the location happens to be here in the u.s. why doesn't he report it to the NHTSA. I hope that is the correct spelling. It looks like though this took place in china? anyway this should be a recall not a tsb as someone can get killed if this happened on the highway or a steep hill into traffic.

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looks like China or Hong Kong, license plates have Chinese characters , but definitely a life safety issue, what if it was a red light at a busy intersection. something like this in the USA would not be ignored by NHTSA. There was an obvious loud bang or squeal at the midway point of the downhill drive like the brake booster gave out due to the increased load of CX-9 weight and trying to hold it back during the downhill run.

actually, I just noticed something, below is YouTube poster's description of what happened, why would anyone shift to "R" in the middle of a downhill run without a full stop ? you would stress the transmission gears immensely wouldn't you ? he finally stopped by shifting to "P". Now knowing more of the details, it doesn;t look like a brake failure but more driver error shifting to "R" on a steep decline.

Mazda CX-9 Control system get broken when I put on the "R" and sliding forward down to the slope with about 50 degree. The control system all down!! No Brake, Steering wheel down. My car still moving forward. Finially, I move to the "P" then the car stopped!! My God, I hope Mazda must fix this issues.

My dad's 2013 Lincoln MKX had a brake booster failure. It was in small town FL, while he was on vacation. Nobody was hurt. Lincoln took care of my dad, gave him a loaner, and fixed his truck in a few days.
Scary scenario.

astriuminc said:

actually, I just noticed something, below is YouTube poster's description of what happened, why would anyone shift to "R" in the middle of a downhill run without a full stop ? you would stress the transmission gears immensely wouldn't you ? he finally stopped by shifting to "P". Now knowing more of the details, it doesn;t look like a brake failure but more driver error shifting to "R" on a steep decline.

Mazda CX-9 Control system get broken when I put on the "R" and sliding forward down to the slope with about 50 degree. The control system all down!! No Brake, Steering wheel down. My car still moving forward. Finially, I move to the "P" then the car stopped!! My God, I hope Mazda must fix this issues.

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This incident happened in Taiwan and probably in Taipei according to the license plate from that outgoing sedan as the driver and passenger in this 2014 CX-9 spoke both Mandarin and Taiwanese. Keep in mind that this CX-9 was almost brand new as this dashcam video was shot in May 17, 2014. I also believe either brake booster or brake system didn't just fail! The interpretation of video poster's description should be when the driver shifed into the Reverse on a steep downhill driveway in a underground parking garage, the vehicle started rolling forward instead! At that time foot brake failed, so as the steering! It seems more likely the engine died so that the driver couldn't feel the foot brake and steering. Luckily the speed was very slow, shifting into the Park did stop the vehicle without breaking the tooth of the flywheel or the locking claw. "Some sort of hissing sound at the end like brake booster failure" is actually tire squeal during the sudden stop with those smooth shining ground surface used in underground garage in Taiwan.

My guess is the engine in this CX-9 simply died for some reason and caused this fiasco! Instead of shifting into Park risking to damage the expensive automatic transmission, the drive should use parking brake first to stop the vehicle!

astriuminc said:

Is this an example of a brake booster failure ? Seems like the guy lost the brakes when he started downhill (there was an unusual sound as he went downhill) he left his foot on the brakes (he's saying: "I can't control it!! I can't control it!!") until he realized in the last seconds to release his foot and press down hard and pump the brakes repeatedly before he smashed into the parked cars there was some sort of hissing sound at the end like brake booster failure. Obvious this isn't a 2016 model, video was shot in 2014, there's a TSB out for the brake booster but no recall?? seems like a dangerous situation, guy was lucky it was a garage and not during a downhill highway emergency stop situation.

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It's not a TSB--there's a warranty extension to, I think, 90,000 miles. There's no recall, I guess because it doesn't happen with enough frequency. But I just had this happen to me, and I brought it to my local mechanic, and he researched it and found the warranty. I immediately took it over to the dealer and got a loaner while they fix it.

Discussed in this thread:

https://www.mazdas247.com/forum/sho...T-FWD-40k-miles-covered-by-warranty-extension!