Thus, to double the output force of the 5 psi (35 kPa) at the master cylinder to 10 psi (69 kPa) at the wheels, simply use a wheel cylinder piston with a surface area of 2 square inches (13 sq.cm). To triple the force of 100 psi (690 kPa), use a piston with 3 square inches (20 sq. cm) and 300 pounds (2068 kPa) of output result (Figure 46-5). No matter what the fluid pressure is, the output force can be increased with a larger piston, though piston travel decreases proportionately. In actual practice