THE CLK has disc brakes all-round, internally ventilated at the front, solid at the rear. The brakes feature hydraulic dual-circuits, a vacuum booster and the BAS Brake Assist System. BAS automatically applies full braking force if the car's brain decides the driver hasn't applied them with sufficient force in an emergency. The development of this system was based on extensive tests carried out in the Daimler-Benz driving simulator in Berlin. Traffic research specialists came to a the conclusion most drivers did not operate the brake pedal vigorously enough in emergency situations.