What type of valve should be cut out when adding helpers?

When adding helpers, it is important to cut out the automatic brake valve. This valve is responsible for regulating the air brakes of the locomotive. When additional locomotives (helpers) are added to a train, the operation of the air brake system needs to be adjusted to accommodate the extra units. Cutting out the automatic brake valve allows for better control and coordination of the braking system across all locomotives involved in the train, which is crucial for maintaining safe and effective braking performance.

In situations where the automatic brake valve is not cut out, it may lead to a mismatch in braking force or potential complications in controlling the entire train's air brake system, especially when helpers are assisting with the train's operation. This adjustment is particularly critical for ensuring that all units talk effectively and provide balanced stopping power.