What action should be taken during overheating to help cool the pump?

To effectively cool the pump during overheating, circulating tank water is the ideal action to take. This method enhances the flow of water through the pump, which in turn helps absorb and dissipate heat. When tank water is circulated, it provides a continuous supply of cooler water, facilitating better thermal management and preventing further damage or degradation of the pump components.

Increasing engine RPM may seem tempting as it might enhance pump performance, but it can also lead to increased heat generation within the system, potentially worsening the overheating situation. Closing all valves can restrict water flow, thereby limiting the cooling effect that could be achieved through circulation. Reducing pressure in the discharge lines may alleviate some stress on the pump but does not directly address the root cause of overheating and does not effectively cool the pump.

Circulating tank water stands out as the most functional approach because it directly addresses the need to reduce temperature by introducing a cooling medium into the system.