NHTSA Complaint #11464246 — 2016 MAZDA MAZDA6

I was driving between 40-50 MPH at a consistent speed and I began to have to put the brake pedal to the floor in order to slow down the car. Even when doing this the car does not slow down at the rate expected and stopping distance has increased by more than 50 percent. Have been told there is Cracked/leaking bore diameter to the master brake cylinder housing is causing pressure and fluid loss, into other internal parts of the braking system. Not visible externally. Mechanic states that they have encountered this problem with several of this year make and model with this exact issue. The shop was able to top off the brake fluid which slightly improved performance but the issue still remains. Car is at 104K miles.