The advantage of having a tandem master cylinder arrangement in automobiles is that it

• enhances safety by serving two independent lines in a divided-line brake circuit
• enhances safety by activating the brakes using vacuum pressure in the event of brake fluid loss
• supplies equal fluid pressure to each line of a divided-line brake circuit, thereby preventing the brakes from dragging on one side
• boosts the brake fluid pressure to reduce the force required to depress the brake pedal