What might indicate a defect in a train's compressors during operations?

The indication of a defect in a train's compressors can often be associated with excessive stopping distance. Compressors play a vital role in generating air pressure for the braking system, and if there is a defect, it can lead to insufficient air being supplied to the brakes. This can cause the brakes to not engage properly, leading to longer stopping distances than what is typical for the train under normal operating conditions.

When brakes require more distance to stop, it suggests that the pneumatic system, which includes the compressors, is not functioning efficiently. This inefficiency can result from various issues within the compressors themselves, such as leaks, mechanical failure, or inadequate pressure generation, all of which directly impact the braking performance and, consequently, the stopping distance.

In contrast, while a sudden loss of speed, unusual engine sounds, or brakes not releasing can indicate other issues in the train's operation, they do not specifically highlight a fault within the compressors as directly as excessive stopping distance does.