During a service application, which component supplies air directly to each car’s brake cylinder?

During a service application, which component supplies air directly to each car’s brake cylinder?

• A. Brake pipe
• B. Auxiliary reservoir
• C. Main reservoir
• D. Control valve

Answer: (B)

Air brakes on each car are actuated by air that comes from the auxiliary reservoir through the car’s control valve. During a service application, the control valve opens and allows this stored air to flow into the brake cylinder, pushing the piston and applying the brakes. The brake pipe mainly serves as the signaling line for braking and releasing, and the main reservoir functions as the overall high-pressure air source that charges the other reservoirs, but it does not directly feed the brake cylinder in a normal service application. That direct supply to the brake cylinder comes from the auxiliary reservoir via the control valve, making it the correct choice.

Air brakes on each car are actuated by air that comes from the auxiliary reservoir through the car’s control valve. During a service application, the control valve opens and allows this stored air to flow into the brake cylinder, pushing the piston and applying the brakes. The brake pipe mainly serves as the signaling line for braking and releasing, and the main reservoir functions as the overall high-pressure air source that charges the other reservoirs, but it does not directly feed the brake cylinder in a normal service application. That direct supply to the brake cylinder comes from the auxiliary reservoir via the control valve, making it the correct choice.