Brakes no Brakes on 2001 Ford Taurus

I went to the store and my brakes worked just fine. When I was leaving the store, I started the car and the brake pedal went to the floor. The brakes engage with the pedal on the floor, but not very well. Any ideas or suggestions?

Asked by for the 2001 Ford Taurus
1 answer
look under the car and look for leakage at wheels and along the driver side of the car also look at the master cylinder where it meets at the brake booster and see if it's wet if it is than the master cylinder is bad