If a hydraulic system shows no pressure, what is likely the issue?

In a hydraulic system, the presence of no pressure can indicate several potential issues, but one of the most common reasons is related to the hydraulic pump. A faulty hydraulic pump directly affects the ability of the system to generate pressure, making it the correct choice in this scenario.

A hydraulic pump is responsible for converting mechanical energy into hydraulic energy by creating flow and pressure within the system. If the pump is malfunctioning, it may not generate any flow or pressure despite the system being otherwise intact. This could be due to internal wear, loss of prime, or mechanical failure of the pump components.

While a broken spring in the relief valve could potentially lead to pressure issues, it primarily functions to maintain safe operational levels by releasing excess pressure when it exceeds a predetermined limit, rather than causing a total lack of pressure. Similarly, a blocked filter would impede flow, but only if fluid attempts to pass through it; it does not inherently prevent pressure generation in the system. Lastly, an open valve could lead to a loss of pressure in certain circumstances but would not be the primary cause of a full failure to generate pressure in a functional hydraulic circuit.

Thus, focusing on the operational mechanics of hydraulic systems highlights how a faulty pump is the most direct source of the issue described in