One problem related to brake master cylinder has been reported for the 2010 Audi Q5. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2010 Audi Q5 based on all problems reported for the 2010 Q5.
My brakes failed on two occasions. When the brake was pressed, the pedal sank all the way to the floor. This happened while the vehicle was in motion. Luckily, on both occasions, the car was moving at less than 25 mph. My ability to slow down was significantly reduced. Ultimately learned that the master cylinder was defective and had to be replaced.