Three problems related to brake master cylinder have been reported for the 1999 Mercury Sable. The most recently reported issues are listed below.
Complete brake failure. Pedal went to the floor and car would not stop. I used the emergency brake to safely stop the vehicle. This happened once before about three years ago and a repair center was unable to duplicate. Brake master cylinder failed and needed to be replaced.
While driving consumer started experiencing problems with brakes, the pedal had to be pushed down further than normal, and the brakes did not seem to work smoothly, while trying to stop for a light, the brakes failed completley and warning signal did not come on, consumer swerved onto the shoulder put the car in low gear and had pedal to the floor and vehicle finally stopped, vehicle was towed in and inspected and it was determined that the master cylinder contained black fluid, and that the cylinder needed to be replaced.
While driving, consumer lost all brakes and brake light came on, dealer found leak in rear cylinder and replaced both cylinders, consumer felt lucky because there was no accident and no injuries.