I just had the pads replaced and it worked fine for awhile but then the red Brake! light came on and the pedal got real stiff. I mean REAL stiff like the power booster is bad. What else could it be if not the booster and is it safe to drive if I maintain a clear distance between me and the car in front of me as I drive it to the repair center. And is this an instance where a used part would be OK? I just put a fortune into a new steering rack and brakes for this car and I'm reluctant to spend too much more as it has 145,000 miles. (I bought it at 119,000) I love the car otherwise but MAN what a lemon.