2012 MAZDA CX-9 Service Brakes Problems

I was driving normally when I started sowing down and noticed the brakes were harder to push. I finally stopped just before almost rear-ending a vehicle in front of me. It turns out the brake booster, a known problem that was not communicated to me a few years ago, failed and makes braking the vehicle harder, increases distance, and makes the vehicle unsafe to drive. The problem has been reproduced via a diagnostic test at Mazda of Gladstone dealership on 9/27/23. The dealership has been the only people who have inspected the issue. There were no warning signs, no warning lights, nothing. It was scary because I didn't think my vehicle was going to stop. It's completely dangerous. I have not gotten the vehicle repaired yet because I believe Mazda holds responsibility as this has been a known issue with their cars.

On August 14, 2020, the brake booster along with the master cylinder failed, resulting in very dangerous and frightening driving conditions, and the parts were replaced with Mazda original parts. This was an ongoing issue with the Mazda CX-9’s. I reported it to the NHTSA, complaint number 11480067. On January 4, 2023, the brake master cylinder and booster failed again resulting again in very dangerous and frightening driving conditions. The car was driven only 25,383 miles before the brakes failed the second time. The Mazda parts were defective and continue to be so after many years with no effort by Mazda to improve these parts. Attached are the repair invoices for both incidents. I have tried contacting Mazda and they refuse to address the issue.

The brakes suddenly became very difficult to press as if I did not have power brakes. No warning lights came on and it became very difficult to stop the car. Then if I had to break suddenly and hard it would stall. I brought it to the repair shop and the brake booster was defective. The brake booster along with the master cylinder had to be replaced. It was a very dangerous and frightening experience the brakes suddenly difficult to use. I contacted Mazda customer service and they did not care. I then tried to escalate the issue over the last two years but it was impossible to contact anyone and all emails came back undeliverable. I just recently learned that I can report this danger to the NHTSA.

Brake power boost failure

This is relating to NHTSA Investigation PE 14-005. Although this car is a 2012 Mazda CX9, my wife driving the car had the same issue where she heard a hissing noise and the brakes were very difficult for her to depress or to stop. A brake issue is a major defect where the NHTSA should have initiated a recall in accordance with 49 U.S.C. 30118-30120, which required notification of all owners. Why the NHTSA allowed Mazda to only issue a 'Special Extended Warranty' is beyond me, and smells of a back door deal. Nonetheless, I was unaware of this issue with the Mazda CX9's as I was never notified. My wife drove the vehicle home and I purchased the replacement parts at my own expense. This should be a full recall and should be reopened as your current investigation PE 14-005 only included years 2010-2011, and did *not* include the...

I was driving along the highway and traffic began to slow. I pushed the brakes and the car did not stop.

Brake booster failure caused a near miss. Wife driving with 5 year old daughter in the vehicle. The stopping force required on the brake pedal became excessive and the stopping (safe braking) distance significantly increased causing emotional distress. My understanding is this part (brake booster) has a defective diaphragm that deteriorates over time. The extended warranty created for this particular issue did not cover the vehicle at the time of the failure.

BRAKE BOOSTER INTERNAL FAILURE - This is a known issue and a safety hazard on Mazda CX 9 models and should be investigated again regardless of the age of the vehicle.

TL* THE CONTACT OWNS A 2012 MAZDA CX-9. THE CONTACT STATED THAT WHILE DRIVING AT APPROXIMATELY 20 MPH, THE BRAKES FAILED TO OPERATE. THE CONTACT MENTIONED THAT THE BRAKES GRADUALLY SLOWED DOWN THE VEHICLE AND STOP INDEPENDENTLY. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THEY INFORMED THE CONTACT THAT THERE WAS AN UNKNOWN RECALL ON THE VEHICLE. THE CONTACT CONTACTED RILEY MAZDA (75 MYRTLE AVE, STAMFORD, CT 06902, (203) 978-5780) AND WAS INFORMED THAT THE VIN WAS NOT UNDER RECALL. THE CONTACT WAS INFORMED OF AN EXTENDED WARRANTY COVERAGE HOWEVER, THE MILEAGE HAD BEEN EXCEEDED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 129,000.

I WAS DRIVING SLOWLY ABOUT 30MIPH AND BEGAN HEARING A HISSING NOISE WHEN I DEPRESSED THE BRAKE PEDAL. ONCE I PULLED INTO MY DRIVEWAY A SMALL INCLINE, AND PUSHED THE BRAKE PEDAL IT WAS VERY TIGHT AND STOPPED AT A POINT, BUT WOULD NOT GO FURTHER, TRIED SHIFTING DIFFERENT GEARS. FINALLY BRAKE DEPRESSED. HISSING HAS CONTINUES, VERY STIFF BRAKE PEDAL

I WAS ON THE INTERSTATE (DRIVING 60+MPH) AND THE CAR IN FRONT OF ME SLAMMED ON THEIR BRAKES FOR AN UNKNOWN REASON. I TRIED TO USE MY BRAKES BUT THEY WERE ROCK HARD AND THE PEDAL WOULDN'T DEPRESS. I WAS FORCED TO SWERVE TO THE RIGHT, STILL HAVING NO BRAKES, AND BARELY MADE IT OVER 3 LANES TO THE SHOULDER OF THE ROAD. IN DOING SO, I CAUSED TOTAL CHAOS AROUND ME, CAUSED A TRACTOR TRAILER TO START TO JACKKNIFE, WHICH CAUSED A CHAIN REACTION BEHIND HIM. IT WAS A TOTAL MIRACLE THAT NO ACCIDENTS WERE CAUSED AND NO ONE WAS KILLED. I CALLED MY MECHANIC FROM THE SIDE OF THE ROAD, HYSTERICAL. HE LOOKED IN HIS DATABASE AND FOUND THAT MAZDA HAD KNOWN ISSUES WITH THEIR POWER BRAKE BOOSTER. I SUBSEQUENTLY FOUND A LETTER FROM MAZDA INSTRUCTING OWNERS "IF YOUR VEHICLE IS FUNCTIONING PROPERLY, THERE IS NO NEED TO...

BRAKE BOOSTER ON VEHICLE WENT OUT WHILE DRIVING, HARD TO ENGAGE BRAKE AND SLOW VEHICLE TO A STOP.

WHILE PULLING INTO MY GARAGE AT LOW SPEED, MY POWER BRAKES FAILED. I HAD TO PRACTICALLY STAND ON THE BREAK PEDAL TO GET THE VEHICLE TO STOP, BARELY STOPPING BEFORE HITTING THE FRIDGE IN MY GARAGE.THE VEHICLE WAS TOWED FOR SERVICE AND THE PROBLEM DIAGNOSED AS THE FAILURE OF THE BRAKE VACUUM BOOSTER.

BRAKE PEDAL HAS BECOME HARDER THAN USUAL TO DEPRESS AND THE CAR DOES NOT START STOPPING UNTIL THE BRAKE PEDAL IS DEPRESSED HARDER AND FURTHER DOWN. ALSO THERE IS A HISSING NOISE ONCE THE CAR STOPS AND THE BRAKE PEDAL GOES FURTHER TO THE FLOORBOARD. ONCE STOPPED AND SITTING THE CAR WILL LURCH AS IF IT HAS BEEN HIT IN THE REAR END. THIS ALL HAPPENS ON ANY TYPE OF ROADWAY. THIS HAS BEEN GOING ON FOR ABOUT TWO MONTHS AND GETTING MORE PRONOUNCED.

WHEN APPLYING BRAKE, HEAR HISSING SOUND DOWN AT FEET. HARD TO STOP, FEELS LIKE PEDAL IS PUSHING BACK. THIS HAPPENS AT ALL SPEEDS, EVEN WHEN PUTTING CAR INTO GEAR FROM PARK. IT HAS BEEN ONGOING FOR ABOUT 2 WEEKS. MECHANIC ADVISED IT IS THE BRAKE BOOSTER.

I WAS DRIVING HOME WITH THE FAMILY AFTER VIEWING SOME HOUSE. EVERY TIME I WOULD STEP ON THE BRAKE PEDAL I WOULD HEAR A HISSING FROM THE BRAKE. BEEN HAPPENING FOR ABOUT A MONTH NOW BUT, WITH THE PANDEMIC GOING ON I JUST DON'T HAVE TIME TO DIAGNOSE THE PROBLEM. WHEN I PRESS ON THE BRAKE IT WOULD STOP LIKE NORMAL WITH AIR HISSING. THE NEXT DAY THE BRAKE PEDAL WOULD FEEL VERY HARD TO PRESS DOWN. LIKE AS IF YOU BEEN PUMPING YOUR BRAKE WHEN THE CAR OFF AND WHEN YOU TURN YOUR CAR ON THE PRESSURE WOULD BE RELEASED. NOT TODAY, IT STAYED HARD AND HARD TO STOP. I HAD TO PRESS THE BRAKE VERY HARD AS IF PRESSING THE BRAKE PEDAL ALL THE WAY DOWN TO THE FLOOR TO MAKE THE CAR STOP. JUST STOPPING AT A RED LIGHT, STOP SIGN, OFF THE HIGHWAY, AND TRAFFIC WAS...

PURCHASED FROM A CERTIFIED PRE-OWNED MAZDA DEALER....I EXPERIENCED, WITH NO WARNING, MY BRAKES BECOME HARD TO PRESS. IT HAPPENS IN REVERSE, COMING OFF CRUISE, SLOW/FAST SPEED, ETC. I HAVE TO USE AN EXTRAORDINARY AMOUNT OF EFFORT TO PRESS THE BRAKES AND BRING THE CAR TO A STOP. IF SOMEONE PULLS OUT IN FRONT OF ME, THERE IS NO GUARANTEE I WOULD BE ABLE TO OPERATE THE BRAKES QUICKLY ENOUGH TO AVOID AN ACCIDENT. I HAVE CHILDREN I TRANSPORT AND IT IS CONCERNING FOR ME AS A MOM ESPECIALLY. A FEW TIMES THE PEDAL WILL 'RELEASE' AND OPERATE NORMALLY AFTER THE EXTRA PRESSURE IS APPLIED WHICH CAUSES THE CAR TO JERK TO A STOP BECAUSE THE BRAKES WERE BEING PRESSED VERY HARD. MOST TIMES, EXTRA PRESSURE IS REQUIRED THE ENTIRE TIME. THIS IS A MAJOR SAFETY CONCERN AND AN ISSUE I AM AWARE IS COMMON IN THIS MODEL. MAZDA EXTENDED THIS...

I AM NOW EXPERIENCING WHAT MAZDA MAILED OWNERS PREVIOUSLY (SEE ATTACHED SSP93 OWNERS NOTICE) REGARDING "POWER BRAKE UNIT WARRANTY EXTENSION PROGRAM SSP 93 2007-2013 MAZDA CX-9". I STRONGLY BELIEVE THAT THIS IS A SAFETY ISSUE SINCE I FIND MYSELF RUNNING STOP SIGNS WHEN I TRY TO STOP THE VEHICLE AT AN INTERSECTION. I KNOW THAT MAZDA EXTENDED THE WARRANTY TO 7 YEARS ON IT'S SSP93 BULLETIN. BUT WHAT HAPPENS TO OWNERS LIKE MYSELF WHO DO NOT FALL WITHIN THAT TIME-FRAME AND ARE NOW EXPERIENCING THIS SAFETY ISSUE? IT IS UNCONSCIONABLE, THAT SINCE MAZDA HAS ACKNOWLEDGED THIS PROBLEM, THAT THE OWNER LIKE MYSELF GETS STUCK WITH THIS SAFETY PROBLEM CONCERNING FAILURE OF THE BRAKING SYSTEM ON THE CX-9. PLEASE ADVISE. THANKS.

AS THE CAR WAS BEING DRIVEN THE BREAKS BECAME HARD AND UNLESS PRESSED VERY HARD IT KEEPS GOING. IT DOESN'T GO DOWN AT ALL. ASSESSMENT SHOWS BRAKE BOOSTER FAILURE. IT IS WEIRD OTHER VEHICLE I HAD ...A TOYOTA NEVER FAILED. I CAN'T DRIVE IT.

BRAKE BOOSTER FAILED. THIS IS A KNOWN ISSUE TO MAZDA. MAZDA SAID TO BRING INTO DEALER FOR ASSESSMENT AND CONSIDERATION FOR GOODWILL WARRANTY REPLACEMENT. DEALER DETERMINED BRAKE BOOSTER FAILED AND MAZDA THEN DENIED GOODWILL CLAIM. I PAID DEALER TO FIX THE ISSUE. THIS IS A MAJOR SAFETY ISSUE AND SHOULD HAVE BEEN RECALLED, NOT GRANTED AN EXTENDED WARRANTY.

POWER BOOSTER HIGH PITCH SOUND WHEN PRESSING BRAKES AND BRAKES ARE HARD WHEN PRESSED THEN GO SOFT AND HARD TO STOP THE CAR.

2012 MAZDA CX-9. CONSUMER WRITES IN REGARDS TO BRAKE POWER BOOST UNIT FAILURE. *LD THE CONSUMER STATED THAT WHEN PRESSING THE BREAK PEDAL THERE IS A HISSING AND THUNK NOISE. THE ENGINE WOULD STALL. THE DEALERSHIP AND MANUFACTURER WERE NOTIFIED, BUT DENIED ASSISTANCE.*JS

BRAKE PEDAL ACTION FEELS SPONGY, SOFT. REQUIRES EXTRA FORCE TO STOP THE CAR WHEN MOVING ON CITY STREETS.

WHEN PUSHING THE BRAKES THE PEDAL IS 'HARD' AS IF THE PEDAL WAS ON THE FLOOR THERE'S A HISSING NOISE LIKE AIR IS LEAKING. IF YOU NEED TO MAKE A SUDDEN STOP IT DOES NOT HAPPEN THE BRAKES ARE SO HARD THE CAR WON'T STOP!! THIS DEFECT HAPPENED SUDDENLY THERE WAS NO GRADUAL WARNING !

SO DISAPPOINTED IN NHTSA FOR NOT REQUIRING MAZDA TO RECALL THE BRAKE BOOSTER FAILURE! NHTSA'S INVESTIGATION INTO THE BRAKE BOOSTER FAILURE WAS CLOSED WHEN MAZDA AGREED TO AN EXTENDED WARRANTY FOR THIS MANUFACTURING SAFETY DEFECT. HAD THE NHTSA PUSHED FOR A RECALL NOTICE, WE WOULD HAVE BEEN ALERTED TO THIS SAFETY DEFECT AND COULD HAVE HAD IT REPAIRED (IT IS KNOWN TO FAIL AROUND 62,000 MILES). WE CONTACTED MAZDA TODAY ABOUT THE WARRANTY ONLY TO BE TOLD OUR VEHICLE WARRANTY EXPIRED LESS THAN 3 MONTHS AGO, RESULTING IN MAZDA'S REFUSAL TO COVER A KNOWN SAFETY DEFECT. MAZDA'S LACK OF COMMITMENT TO RESOLVING THIS SAFETY ISSUE IS SHOCKING. NHTSA'S ACCEPTANCE OF MAZDA EXTENDING ITS WARRANTY FOR THIS KNOWN SAFETY ISSUE IS DISHEARTENING AS WELL. A MANUFACTURING DEFECT IS A MANUFACTURING DEFECT; THE PROBLEM SHOULD HAVE BEEN ADDRESSED WHEN IT FAILED OR, AT THE VERY LEAST, RECALLED AND REPLACED. A TIME LIMIT...

TL* THE CONTACT OWNS A 2012 MAZDA CX-9. WHILE ATTEMPTING TO ACCELERATE FROM A TRAFFIC LIGHT, THE ACCELERATOR PEDAL WAS DEPRESSED; HOWEVER, THE VEHICLE FAILED TO RESPOND. THE CONTACT STATED THAT THERE WERE NO WARNING INDICATORS BEFORE OR AFTER THE FAILURE. THE BRAKE PEDAL ALSO BECAME EXTREMELY DIFFICULT TO DEPRESS. THE VEHICLE WAS TOWED TO CONTINENTAL MAZDA (LOCATED AT 2363 AURORA AVE, NAPERVILLE, IL 60540, (630) 352-5900) WHERE IT WAS DIAGNOSED THAT COOLANT ENTERED THE ENGINE OIL AND CAUSED THE ENGINE TO FAIL. THE CONTACT WAS INFORMED THAT THE ENGINE NEEDED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOTIFIED AND PROVIDED CASE NUMBER: 1-2189354066. THE APPROXIMATE FAILURE MILEAGE WAS 52,000.

APPLYING BRAKES FOR 1-2 SECONDS RESULTED IN NO IMMEDIATE STOPPING, ONLY RESISTANCE FROM THE PEDAL. AFTER 1-2 SECONDS, THE BRAKES WERE AGGRESSIVLY APPLIED. THIS RESULTED IN "RUNNING A STOP SIGN" AND STOPPING THE IN MIDDLE OF AN INTERSECTION. THIS OCCURRED ON A CITY STREET MULTIPLE TIMES BEFORE GETTING THE CAR TO A REPAIR SHOP. ON HIGHWAYS, BRAKING HAD TO BEGIN WELL IN ADVANCE TO AVOID POSSIBLE CRASHES. WE HAD TO HAVE THE MASTER CYLINDER AND BRAKE BOOSTER REPLACED. THE VEHICLE HAS 55K MILE ON IT.

BRAKES SLIP CAUSING UNEXPECTED INCREASE IN STOPPING DISTANCE EVEN AT LOW SPEED. VERY CONCERNED ABOUT FAMILY SAFETY. RESEARCH FOUND ISSUE WAS NOTED PREVIOUSLY AND SUPPOSEDLY CLOSED, BUT MANY COMPLAINTS LIKE MINE HAVE BEEN FILED SINCE. HOW MANY DEATHS MUST NHTSA SEE REPORTED UNTIL THEY TAKE ACTION AND RECALL THIS ADMITTEDLY FAULTY DESIGN?

I PUT MY VEHICLE IN THE MAZDA SHOP LAST YEAR 2017 FOR A RECALL AND I MENTIONED THAT THERE WAS SOMETHING I FELT IN MY BRAKES THEY TOLD ME THAT IT MAY BE DUST AND BY DRIVING IT WILL GO AWAY,MAZDA KNEW ABOUT THIS PROBLEM THEY SHOULD HAVE TAKEN CARE OF IT THEN.MY VEHICLE WAS TAKEN TO OURISMAN MAZDA DEALERSHIP ABOUT 2 WEEKS AGO AND I WAS TOLD THAT IT WAS MY BRAKE BOOSTER & MASTER CYLINDER LABOR IS $709.47 AND THE PARTS ARE $537.98 AND THE BRAKE FLUSH IS $202.61 TOTAL $1450.06 AND MY WARRANTY EXPIRED IN OCTOBER 2018. I THEN CALLED MAZDA AND I SPOKE TO A MS.JENNIFER A CUSTOMER EXPERIENCE REPRESENTATIVE AND SHE SAID SHE WOULD CHECK INTO IT.I THEN CALLED BACK TO OURISMAN MAZDA AND SPOKE TO MR.EMERSON AND HE TOLD ME THAT HE SPOKE TO MS JENNIFER AT MAZDA AND THAT MY OUT THE DOOR...

BRAKES WERE OCCASIONALLY 'TIGHT', HAD TO BE PUSHED VERY HARD TO GET THE VEHICLE TO STOP. WHEN I PUSHED THE BRAKES IT SOUNDED LIKE AIR WAS BEING PUSHED OUT. CHANGED PADS AND BRAKE FLUID, FLUSHED THE AIR OUT. ONLY MADE IT WORSE. NOW THE BRAKES ARE CONSTANTLY 'TIGHT' AND AFTER LEARNING THIS IS A COMMON ISSUE WITH THIS VEHICLE I'M GOING TO REPLACE THE BRAKE BOOSTER. RIDICULOUS THAT SO MANY ARE HAVING THIS ISSUE AND MAZDA ISN'T RECALLING THIS PART!

VACUUM POWER BRAKE BOOSTER FAILURE, MY BRAKES DID NOT WORK AND MY CAR STALLED. THERE IS A WARRANTY EXTENSION FOR THIS PROBLEM - NOT A RECALL - I NEVER KNEW ANYTHING ABOUT IT. A CONSUMER MUST BE NOTIFIED OF A RECALL BUT NOT A WARRANTY EXTENSION BUT THIS IS A VERY DANGEROUS PROBLEM. I FEAR FOR THE SAFETY OF OTHERS WHO MAY NOT KNOW ABOUT THE PROBLEM. IF YOU DON'T KNOW ABOUT IT YOU DO NOT ASK TO HAVE IT CHECKED AND WHEN IT FAILS YOU ARE IN DANGER. I APPRECIATE THE WARRANTY EXTENSION BUT I HONESTLY THINK THAT I SHOULD HAVE BEEN NOTIFIED. NO ONE WAS INJURED AND THERE WAS NO PROPERTY DAMAGE - I BELIEVE THERE SHOULD BE SOME RECONSIDERATION REGARDING THE DECISION NOT TO ISSUE A RECALL ON THIS PROBLEM.

THE BREAK BOOSTER WENT OUT WITHOUT WARNING AND COULD NOT STOP THE VEHICLE

TL* THE CONTACT OWNS A 2012 MAZDA CX-9. WHILE DRIVING 35 MPH, THE BRAKE PEDAL WAS DEPRESSED, BUT FAILED TO ENGAGE. THE VEHICLE WAS EXAMINED BY AN INDEPENDENT MECHANIC WHO DIAGNOSED THAT THE POWER BRAKE BOOSTER NEEDED TO BE REPLACED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS 110,000.

I PARKED MY MAZDA AFTER COMING BACK FROM MY LUNCH BREAK AND NOTICED THAT MY BRAKE PEDAL WAS A LOT HARDER TO PUSH. I ALSO HEARD A NOISE COMING FROM WHAT SEEMED LIKE THE PEDAL. IT SOUNDED LIKE I WAS LETTING AIR OUT OF A BALLOON. AFTER WORK, WHILE DRIVING IN REVERSE TO BACK OUT OF MY PARKING STALL, I NOTICED THE BRAKES WERE STILL VERY HARD TO PUSH. THE NOISE WAS ALSO STILL HAPPENING, BUT IT WAS LOUDER. I DECIDED NOT TO DRIVE MY VEHICLE UNTIL I HAD IT LOOKED AT BY A MECHANIC. WHEN MY MECHANIC STARTED MY VEHICLE AND BEGAN TO TEST DRIVE IT, THE NOISE WAS GONE, BUT HE ALSO FELT THAT IT WAS VERY HARD TO APPLY MY BRAKES. THE PROBLEM WAS DIAGNOSED AS A BAD BRAKE BOOSTER. AFTER THE PROBLEM WAS DIAGNOSED, I RESEARCHED COMMON COMPLAINTS WITH THIS, AND DISCOVERED THAT IT IS ALSO...

LETTER FROM SENATOR GARDNER ON BEHALF OF CONSTITUENT REGARDING HIS CONCERNS ABOUT A DEFECTIVE BRAKE DESIGN SYSTEM WHICH EXISTS IN THE MAZDA CX-9. *LD *JS

VIRTUALLY COMPLETE LOSS OF BRAKING. QUICK ONSET. APPARENTLY THE SAME UNDERLYING DEFECT AS INVESTIGATED IN 2008-2011 (INCORRECTLY CLOSED) AND IN TSB #SSP93 NHTSA ID #10117767. THE DEALER HAD THE CAR IN FOR ANOTHER ISSUE (RECALL) IN MARCH; BUT DID NOT FIX THIS ISSUE (NOT ALLOWED TO SPEAK OF IT -- UNLESS THE CUSTOMER BRINGS IT UP (PERSONAL COMMUNICATION 7/3/2018). NHTSA STAFF SHOULD HAVE NOTICED THAT THE 2012 TSB IS ESSENTIALLY A CONTINUATION OF THE CORE ISSUE FROM 2008 ONWARD. A FAILING BOOSTER SHOULD INCREASE THE EFFORT TO BRAKE, IT SHOULD NOT BE PERMITTED TO RESULT IN COMPLETE LOSS OF FUNCTIONALITY!

AT JUST OVER 90,000 MILES I HAD TRANSFER CASE PROBLEM THAT EVERYONE IS POSTING. AS DESCRIBED BY MECHANIC IT IS A MANUFACTURING DEFECT. TRANSFER CASE IS PLACED JUST ABOVE CATALYTIC CONVERTER (WHICH THROWS OFF ALOT OF HEAT) AS A RESULT OIL IN TRANSFER CASE COOKS OVER TIME AND GEARS ARE DESTROYED. MAZDA DID NOT PROVIDE A WAY TO REPLACE AND OR CHECK THIS FLUID WITHOUT TAKING DOWN THE ENTIRE TRANSMISSION. MECHANIC SAID I WILL HAVE THIS PROBLEM AGAIN AT ROUGHLY ANOTHER 80-100,000 MILES. YEAR AND A HALF LATER I NOTICED A VERY SOFT BRAKE. I REPLACED BRAKE PADS AND DRUMS, AND BRAKE FLUID. I HAVE A VERY HARD BRAKE WHICH THEN SPORATICALLY GOES SOFT. AGAIN I LOOKED UP THIS ISSUE AND FOUND AGAIN MAZDA IS AWARE OF THIS ISSUE AND EXTENTED WARRANTY TO 90,000 MILES. AGAIN I'M JUST OVER THE WARRANTY ALLOWANCE AND NOW MY BRAKE POWER BOOSTER AND POSSIBLY...

I WAS DRIVING TO GET LUNCH FROM WORK AND WENT TO STOP AT AT TRAFFIC LIGHT ON A VERY BUSY ROAD AND MY VEHICLE WOULDN'T STOP. THE PEDAL WAS HARD AND I HAD TO PUSH IT ALL THE WAY DOWN AND NARROWLY MISSED THE VEHICLE IN FRONT OF ME. I DROVE CAREFULLY BACK TO WORK AND HAD THE VEHICLE TOWED TO THE SHOP. IT WAS THE BRAKE BOOSTER. I THEN DID SOME RESEARCH ON THE SUBJECT SINCE MY VEHICLE IS STILL FAIRLY NEW AND IT SEEMED ODD. I SAW SO MANY COMPLAINTS AND IT SCARED ME. THIS NEEDS TO BE RECALLED BEFORE SOMEONE GETS SERIOUSLY HURT!!

APPLY WITH THE BRAKE PEDDLE IS PRESSED. CAN WILL CONTINUE ROLL, AND IN SOME CASES, BECOME VERY HARD TO STOP. SO FAR, NOT HIT ANYTHING, BUT HAVE HAD ISSUES ON NOT BEING ABLE TO STOP AT STOP LINES EVEN AT SLOW SPEEDS.

THE BRAKING SYSTEM DID NOT FUNCTION CORRECTLY RESULTING IN A CRASH. BRAKES WERE HARD AND COULD NOT BE DEPRESSED WHEN A VEHICLE STOPPED QUICKLY IN FRONT OF ME. TOOK THE CAR TO MAZDA DEALERSHIP AND THEY INFORMED ME THAT THIS IS A KNOWN PROBLEM AND REPLACED THE BRAKE BOOSTER UNDER A "SPECIAL WARRANTY". THIS NEEDS TO BE A SAFETY RECALL, I WAS NEVER NOTIFIED OF THIS SAFETY ISSUE. IT IS IMPERATIVE THAT NHTSB REOPEN THE INVESTIGATION ON THIS PROBLEM AS IT DOES NOT ONLY INVOLVE 2010 AND 2011 CARS AND DOES NOT ONLY OCCUR IN "HIGH AMBIENT TEMPERATURES". VEHICLE WAS IN MOTION AND WAS SLOWING ON AN SLIGHT UPHILL GRADE. VEHICLE IS 5 YEARS OLD AND HAS 53,000 MILES.

I WAS GOING 10MPH TO STOP IN FRONT OF MY DAUGHTER'S SCHOOL TO PICK HER UP WHEN MY BRAKES WERE DIFFICULT TO APPLY. I HAD TO USE BOTH OF MY FEET TO STOP MY CAR FROM CRASHING INTO THE CAR IN FRONT OF ME. I HEARD A HISSING SOUND WHEN I APPLIED MY BRAKE. THE LIGHTS ON MY DASH ABS LIT UP AND THEN MY CAR SHUT OFF. I WAS SCARED AND DIDN'T KNOW WHAT HAPPENED. I WAITED A FEW MINUTES WHEN NO ONE WAS IN FRONT OF ME AND TRIED TO DRIVE AWAY AND IT HAPPENED AGAIN. I LEFT MY CAR AT A GAS STATION FOR A TOW TRUCK TO GET IT. I WAITED FOR THE CAR TO BE TOWED AND GOOGLED WHAT HAPPENED. TURNS OUT OVER 50 OTHER PEOPLE HAVE HAD THE SAME ISSUE HAPPEN WITH THE SAME CAR AND YEAR. THE BRAKE BOOSTER ASSEMBLY WENT OUT BETWEEN...

BRAKES DO NOT STOP VEHICLE IMMEDIATELY, IT IS HARD TO APPLY BRAKES.

THE MAZDA CX9 THAT WE PURCHASED HAS A ACCELERATION PROBLEM WHEN WE GO TO STOP.. MAZDA HAS NEVER BEEN ABLE TO SOLVE THE PROBLEM COMPLETELY.. WE HAVE HAD 2 BRAKE BOOSTERS REPLACED UNDER WARRANTY. WE FEEL THE CAR IS UNSAFE TO DRIVE AND MAZDA HAS NOT ADDRESSED THE PROBLEM. THEY TELL US NOTHING IS WRONG WITH THE CAR. IT KNOW ALSO HAS TRANSMISSION PROBLEMS WITH SQUEAKING AND GRINDING NOISES COMING FROM THE CAR. THIS IS A DESIGN FLAW THAT HAS NOT BEEN ADDRESSED.

AIRBAG SAFETY RECALL, TRANSMISSION SWITCH FAILURE, THROTTLE BODY FAILURE, BRAKE FAILURE

POWER BOOSTER MASTER CYLINDER FAILURE. FIRST, SPONGY PEDAL ATTRIBUTED TO MASTER CYLINDER WITH NO FLUID PRESENT. AFTER REFILLING HYDRAULIC FLUID, PEDAL WAS BETTER FOR A DAY OR TWO THEN LOUD NOISE COMING FROM CABIN IN VEHICLE WHEN PEDAL IS DEPRESSED. (IT GOES TO THE FLOOR AND BECOMES VERY LOUD.) SOUNDS LIKE AN IDENTICAL PROBLEM TO EARLIER MODEL YEAR.

BRAKE BOOSTER, HISSING NOISE AND HARD BRAKE. NO WARNING, BRAKES DON'T STOP WELL. BRAKE BOOSTER CONTINUES LOSING VACUUM PRESSURE AS LONG AS THE BRAKE IS APPLIED. I HAVE NOTICED ONLINE MULTIPLE COMPLAINTS AND A KNOWN PROBLEM.

HISSING SOUND WHEN BRAKING IN MOTION OR PARKED. WHEN DRIVING UP TO AN INTERSECTION AFTER EXITING THE FREEWAY ABOUT 20 MPH CAR WOULD NOT STOP NO MATTER HOW HARD I STEPPED ON THE PEDDLE. LUCKILY I WAS ABLE TO SLOW BEFORE HITTING THE CAR IN FRONT OF ME. WHEN STOPPED AT A LIGHT CAR LUNGED FORWARD WHILE MY FOOT WAS ON THE BRAKE. THIS HAPPENED AGAIN WHILE I WAS WAITING FOR MY DAUGHTER AT SCHOOL. IT LUNGED UP AND NEARLY HIT THE CAR IN FRONT OF ME! SCARIEST THING IN THE WORLD TO NOT BE ABLE TO BRAKE!!

WHEN BRAKING THE BRAKES ARE EITHER HARD AND DO NOT WORK OR BRAKES ARE SPONGY, WILL SLOW VEHICLE, BUT WILL NOT GIVE YOU CONFIDENCE THAT THEY WILL STOP THE VEHICLE LIKE THEY SHOULD. WHEN BRAKING AT TIMES YOU CAN HEAR A HISSING, MAYBE ALL THE TIME, BUT WHEN THINGS ARE HAPPENING YOU AREN'T LISTENING FOR A HISSING SOUND. ALSO, WHEN THE VEHICLE IS STATIONARY AND IN PARK IF YOU REALLY PUT YOU FOOT TO THE FLOOR A BEEPING ALMOST LIKE AN ALARM SOUND IS MADE. THIS BRAKE BOOSTER FAILURE SHOULD BE A MAJOR CONCERN. 8-13-2017 I WAS TRAVELING ABOUT 65 MPH IN LITE TRAFFIC ON A DOWNGRADE AND SLIGHT CORNER WHEN A VEHICLE IN FRONT OF ME LOST A TIRE AND I NEEDED TO BRAKE QUICKLY AND MY BRAKE PEDAL WOULDN'T MOVE, IT WAS HARD AS A ROCK, NEVER SLOWED THE VEHICLE AT ALL. THANK GOODNESS I HAD PLENTY OF...

WHEN STEPPING ON THE BRAKE PEDDLE A HISSING SOUND IS HEARD AND THE BRAKES NO LONGER STOP THE CAR.

THE CAR BREAKS BECAME HARD TO PUSH STARTED HISSING AND WOULDN'T RESPOND TO BREAK TILL THE PEDAL WAS ALMOST PUSHED TO THE FLOOR. THERE WAS NO WARNING. WE WERE ON THE HIGHWAY.