Final answer:
The B pumps with HYDRAULIC B pump switches in AUTO mode automatically operate to maintain correct hydraulic pressure, activating when the pressure falls below the necessary level.
Step-by-step explanation:
When HYDRAULIC B pump switches are in AUTO mode, the B pumps will operate automatically to maintain the required hydraulic pressure within the system. This is particularly essential in heavy machinery, such as power brakes or bulldozers, where a motorized pump exerts most of the work to ensure the system operates efficiently. If the system's sensors detect a fall in pressure below the optimal level, the B pumps will engage to restore it, thereby preserving the functionality of the equipment.