What kind of system primarily operates the air brakes in heavy vehicles?

Air brakes in heavy vehicles primarily operate through a pneumatic system. Pneumatic systems utilize compressed air to create the necessary force for braking. This process begins with air being compressed in a storage tank and then released through a series of valves and chambers that activate the brakes.

The advantage of pneumatic systems for heavy vehicles is that they are capable of generating a significant amount of braking power without the risk of fluid leaks that can occur in hydraulic systems. Additionally, the use of air as a medium means that the system can be self-reinforcing: as air pressure builds up, the braking force increases, which is particularly useful for large and heavy vehicles that require substantial stopping power.

In contrast, hydraulic systems rely on fluid pressure to operate brakes and are typically found in lighter vehicles. Electric systems are more commonly applied in automotive applications for smaller vehicles and are not suitable for the high demands of heavy vehicle braking. Mechanical systems use physical components like cables and levers, which are less efficient in delivering the same level of braking force required in heavy vehicles. Consequently, the pneumatic system is the optimal choice for the operation of air brakes in heavy vehicles.