I have a 2001 Taurus SEL with an automatic transmission, ABS and approximately 75,000 miles. The master cylinder was replaced within the last 5,000 miles. Following replacement of the master cylinder, an unusual problem has occurred on an intermittent basis. After the car has been driven for a few miles, the brake pedal will become very stiff and firm (e.g. rather grabbing about a third of the way down, the brakes will grab with very light pressure on the pedal). In addition, if the car is being driven at highway speeds (60-65 mph), the steering wheel will vibrate. Lastly, the car will feel as if it is being driven in the wrong gear (loss of torque). This condition will last for several miles and then disappear for no apparent reason. Otherwise, the car runs fine. I know the symptoms sound unusual but this has been happening for several weeks with no apparent cure.