Brake Master Cylinder problems of the 2006 Mercury Milan

In more than one instance the brakes have suddenly gone "soft", making it very difficult to break. One time the driver went over a bumpy area in the road and two other times it occurred when the roads were wet. The most recent incident resulted in rear-ending another car. In the most recent incident, the driver was heading north on governor's square boulevard towards e. Magnolia drive in tallahassee, FL. It was raining lightly and the roads were wet. The driver was within the posted speed limit of 35 mph. As the driver approached the intersection, the light was red. When the driver hit the brakes the pedal went "soft" and she had to push it as hard as possible to continuing braking. Though the car was slowing, it was not able to stop before the reaching other cars at the intersection. The result was that the car rear-ended another car which then pushed into another car in front. The drivers of the 2 other vehicles stopped, police came, and a crash report was issued. We determined it would be best to leave the car parked until it could be determined if the brakes would recover. When we returned the following day, the brakes appeared to be functioning properly, but in an abundance of caution, the driver is not driving the car. In the previous 2 occurrences of the brake problems, we brought the car to an auto repair shop. The first time, no problems could be found (date could be provided with auto records). The second time (around may 2017), it was diagnosed as a master cylinder and that was part was replaced and the repair completed. Between the first and second incident, the brake system was completely redone as regular maintenance on the car. So, the correction work performed and regular maintenance, were not successful in addressing the issue.

I had to replace the brake booster,cv boots, master cylinder rotors and brakes. All to the tune of 2,000. I had no warning. No lights in the dash came on or anything. I was going down a hill and all of a sudden there were no brakes. I have had cars and drove them for over 200,000 miles and I have never had to replace all this stuff on a car. This Mercury has cost me so much money. Its not like its a mercedes or BMW. Nothing on this car is cheap to get fixed. I have replaced the brakes over 20 times and the car is only 6 years old. I see why they stopped making them.