<Li> <P> Four way protection valve </P> </Li> <P> Four way protection valve </P> <P> Air brakes are used as an alternative to hydraulic brakes which are used on lighter vehicles such as automobiles . Hydraulic brakes use a liquid (hydraulic fluid) to transfer pressure from the brake pedal to the brake shoe to stop the vehicle . Air brakes have several advantages for large multitrailer vehicles: </P> <Ul> <Li> The supply of air is unlimited, so the brake system can never run out of its operating fluid, as hydraulic brakes can . Minor leaks do not result in brake failures . </Li> <Li> Air line couplings are easier to attach and detach than hydraulic lines eliminating the risk of air getting into hydraulic fluid since there is no hydraulic fluid . Air brake circuits on trailers can be easily attached and removed by operators with appropriate training . </Li> <Li> Air not only serves as a fluid for transmission of force, but also stores potential energy . So it can serve to control the force applied . Air brake systems include an air tank that stores sufficient energy to stop the vehicle if the compressor fails . </Li> <Li> Air brakes are effective even with considerable leakage, so an air brake system can be designed with sufficient "fail - safe" capacity to stop the vehicle safely even when leaking . </Li> </Ul>

What is the difference between air brakes and hydraulic brakes