What does the Full Service Position do to the equalizing reservoir and brake pipe pressures?

The Full Service Position is designed to bring the equalizing reservoir and brake pipe pressures to a state of near equalization. When the brake is applied in the Full Service Position, it allows for a controlled reduction in brake pipe pressure while simultaneously allowing the equalizing reservoir to adjust accordingly. This process eventually leads to both pressures moving closer together, which is crucial for efficient braking performance throughout the train. Attaining near equalization helps ensure that the brakes can effectively operate across all cars, thus enhancing safety and control during train operation.