What happens when the hydraulic pump is not operating?

When the hydraulic pump is not operating, the accumulator supplies power for limited operation. This is because hydraulic systems typically incorporate an accumulator to store hydraulic fluid under pressure, which can be used to maintain system functions even when the pump is not actively circulating fluid.

Accumulation allows for temporary operation of hydraulic systems, ensuring that certain critical functions can continue for a limited time, depending on the capacity of the accumulator and the demands of the system. This stored energy is essential for maintaining hydraulic pressure during situations like pump failure or maintenance.

The other options do not accurately describe the function of the hydraulic system under these conditions. The accumulator does not lose all pressure immediately (as stated in the first option), nor does the system run indefinitely without the pump (as indicated in the third option). The fourth option suggests contamination of the fluid, which is not a direct effect of the pump being off. Instead, the accumulator's role is to provide temporary pressure support, making the second choice the most accurate.