We just experienced a total brake failure with our wagon, 51,000 miles. Pedal went to the floor while driving (rear ended the car in front), then normal braking function resumed. Car was serviced mid-February. Brake pad and fluid levels are fine but 'Brake Fluid' warning lamp has occasionally flashed a few times each week since the service. What can cause the brake fluid warning lamp to go on other than low brake fluid??? Dealer will pick up car tomorrow.