One problem related to brakes failed has been reported for the 1999 Mercury Sable. The most recently reported issues are listed below.
Was driving in stop-and-go traffic near holland tunnels in nyc when brakes failed without warning. Went to stop and pedal traveled completely to floor. Had to use emergency brake to stop. 2 hour wait for tow truck, so decided to try driving again after 1 hour. Brakes appeared to function normally thereafter, although a little spongy at first.