1. Air Compressor: The air brake system begins with an air compressor driven by the vehicle's engine. This compressor generates compressed air and stores it in an air reservoir (air tank).
2. Air Reservoir: The air reservoir is a cylindrical tank designed to hold compressed air under high pressure. It acts as a storage vessel, ensuring a ready supply of compressed air for the braking system.
3. Brake Control Valve: The brake control valve, also known as the foot valve, is located inside the vehicle's cab and is operated by the driver. When the driver steps on the brake pedal, they activate the brake control valve.
4. Control Lines: Control lines are air lines that connect the brake control valve to the brake chambers on each wheel. These lines carry pressurized air from the air reservoir to the brake chambers when the brake control valve is actuated.
5. Brake Chambers: Each wheel has a brake chamber, which is a cylindrical housing containing a diaphragm and a pushrod. The control lines from the brake control valve deliver pressurized air to the brake chambers.
6. Diaphragm and Pushrod: Inside the brake chamber, the pressurized air pushes against the diaphragm, causing it to move. This movement activates the pushrod, which is directly connected to the brake shoes or brake pads.
7. Brake Shoes or Brake Pads: The pushrod forces the brake shoes or brake pads against the rotating brake drum or brake rotor, respectively, creating friction that slows down or stops the vehicle.
8. Return Springs: When the driver releases the brake pedal, the brake control valve closes, and the air pressure in the brake chambers is released. Return springs pull the brake shoes or brake pads away from the brake drum or brake rotor, releasing the brakes.
9. Automatic Slack Adjusters: To compensate for wear on the brake shoes or brake pads, most modern air brake systems incorporate automatic slack adjusters. These devices maintain the proper clearance between the brake components to ensure optimal braking performance.
10. Parking Brakes: Air brake systems also include parking brakes, which are typically spring-applied and air-released. When the parking brake is engaged, it locks the brake chambers in place, preventing the vehicle from moving.
The air brake system relies on the appropriate supply of compressed air to function correctly. If there's a leak in the air lines or a problem with the air compressor or any other component, the air brake system may be compromised, affecting the vehicle's braking capabilities. Therefore, it's essential to regularly maintain and inspect air brake systems to ensure they are in proper working condition for safety on the roads.
