AUGUST 6TH 2013 MY WIFE COMPLAINED ABOUT THE BRAKES ON HER 2011 MAZDA CX9 MAKING A HISSING TYPE SOUND AND BRAKES FEELING MUSHY AND NOT RESPONDING AS NORMAL. THE NEXT DAY SHE ADVISED THE BRAKES WERE WORSE SO WE PARKED THE CAR UNTIL THE 9TH. THE CX9 HAS 46000. MILES. THE CAR RECEIVES REGULAR MAINTENANCE AND WAS TAKEN TO TOM BUSH MAZDA (JACKSONVILLE FL.) FOR DIAGNOSIS OF THE PROBLEM. WE WERE ADVISED THAT THE ISSUE WAS A VACUUM LEAK FROM THE BRAKE BOOSTER AND IT HAD TO BE REPAIRED AT THE COST OF $695.88. (PART = $130. W/ LABOR $503.) WE LEARNED THAT OTHERS HAVE HAD THE SAME PROBLEM AND THAT A RECALL MIGHT HAVE BEEN ISSUED FOR THE PREVIOUS YEAR CX9S. THERE WAS NO CONSIDERATION ON REPAIR COSTS. OUR ISSUE IS THE BRAKE VACUUM BOOSTER FAILURE SEEMS TO BE AN ABNORMALLY COMMON COMPLAINT ON MAZDA'S CX9 VEHICLES AND THE FACT THAT THIS INVOLVES BRAKE FAILURES, IS A SAFETY ISSUE THAT MAY LEAD TO A CATASTROPHIC CRASH AT HIGHER SPEEDS. I BELIEVE OTHER SIMILAR COMPLAINTS NOTED ABOUT MAZDA CX9 BRAKE ISSUES IN THE NHTSA WARRANT A THOROUGH INVESTIGATION AND POSSIBLE RECALL. WE WILL RETAIN THE DEFECTIVE PART. FURTHER NOTE, THE MAZDA DEALERSHIP RELEASED THE VEHICLE TO MY FATHER W/O PROPERLY INSPECTING THEIR WORK. THE VEHICLE WAS RELEASED TO US W/O THE BRAKE LINES BEING BLED PROPERLY WHICH CAUSED THE BRAKES TO FAIL WHILE AT THE DEALERSHIP. IT TOOK ANOTHER DAY TO FIX THAT ISSUE. *TR