Question 122General Subjects - 1st Asst/Chief

The correct answer is A) cavitation. If a hydraulic pump sounds like it is pumping rocks when in operation, the problem is most likely cavitation. Cavitation occurs when the pump is not able to provide enough suction to the fluid, causing the fluid to vaporize and create bubbles that implode against the pump components, leading to the "pumping rocks" sound. This is often caused by issues like a clogged suction line, low fluid level, or worn pump components. The other options are incorrect - slippage refers to fluid leaking past the pump's internal seals, galvanic action is an electrochemical reaction causing corrosion, and none of those would specifically cause the "pumping rocks" sound that indicates cavitation.