Brake classification - Air brakes Video

Air brakes work using compressed air instead of hydraulic fluid. Air brakes can be either drum brakes or disc brakes, or a combination of both. Air is pressurized by an engine-mounted compressor. The air compressor then pumps the air into the air storage tanks, which store the compressed air until it’s needed. Air pressure is used to apply the service brakes and release the parking brake. There are multiple air circuits in the system. The parking brake engages by spring force in the parking brake portion of the spring brake chamber when the air pressure in the chamber is released. This also allows the parking brake to be used as the emergency brake system. If air pressure was to drop too low, the force exerted by the spring in the chamber will be able to overcome the force exerted by the air on the diaphragm and apply the brakes on all wheels. You might think of air brakes as working similarly to a hydraulic brake circuit. As with hydraulic brakes, when the driver presses the brake pedal, air pressure is applied, like hydraulic pressure in a hydraulic brake circuit to the wheel when applying the brake.

Advantages of  air brakes Disadvantages of air brakes Air brakes are a lot easier to connect than hydraulic brakes and using air instead of hydraulic fluid prevents many potential malfunctions. Minor leaks in the brake lines won’t cause a complete failure of the system, and air brakes can even function despite major leaks. Since air supply is unlimited, the system isn’t at risk of running out of the active braking substance. In event of complete air loss brakes will be activated to prevent any movement. Great braking power Easy to connect multiple trailers to truck (horse) for effective braking Air is fast acting, even over long distance Leaks will not lead to pollution The compressed air inherent in the system can be used for accessory applications that hydraulics are not appropriate for, such as air horns, bus door operation and seat adjusters. Air brakes generally cost more. Air brake systems compress air, which results in moisture that requires air dryers to remove, which also increases the price for air brake systems and can contribute to higher maintenance and repair costs. Defective air dryers lead to ice in the air brake system in cold locations. Commercial drivers are required to obtain additional training and licensing, known as an endorsement, in order to legally drive any vehicle using an air brake system. Learning to operate air brakes smoothly has a learning curve, as they are difficult to operate smoothly. Also, since air brakes must be operated differently from hydraulic systems, driving a vehicle with air brakes requires knowledge of proper maintenance. A driver is required to inspect the air pressurization system prior to driving and make sure all tanks are in working order. Noise Pollution