What air brake test(s) will be required after adding a locomotive to your train?

• A. Leakage test
• B. Service test
• C. Emergency brake test
• D. Application and release class III

Answer: (D)

When you add a locomotive to a train, you must verify that the locomotive’s braking system responds correctly to brake commands. That’s done with the Class III Application/Release test. This test specifically checks that the locomotive brake can be applied and released in response to the train’s brake control signals and that the brake pipe and related systems behave properly with the new locomotive tied in. It ensures the locomotive will contribute the intended braking force to the train before you move.

Other tests exist in the overall air brake program — a leakage test checks for air leaks with brakes released, a service test confirms the train can stop under normal braking, and an emergency brake test ensures full emergency braking works. These are important but, in the context of simply adding a locomotive to the train, the required focused check is the Class III Application/Release.