Hydraulic Troubleshooting — real-world interview & field troubleshooting questions with clear, practical answers. Tap any question to open its answer. Showing the first 70 questions free. The complete question bank is available as a PDF below. Pump & System Pressure Q1 The hydraulic system pressure is much lower than the normal operating pressure. What should you check first? Answer Check the pressure-gauge reading, pump rotation, pump inlet condition, relief-valve setting, suction restriction, oil level, and obvious leakage. Compare pump output pressure with the required system pressure before changing the relief setting. Q2 The hydraulic pump is running but the actuator does not move. What would you investigate? Answer Check whether the pump is actually producing flow, then inspect directional-valve operation, supply pressure, flow-control settings, blocked lines, actuator condition, and any mechanical obstruction. Q3 The hydraulic pump makes a loud whining noise during ...