• Keep the pump exterior clean from dust and oil污.
• Check oil levels before start-up and during operation.
• Listen for abnormal noises during operation, which may indicate internal issues like part wear or looseness.
• Regularly record operating parameters like pressure, flow, and temperature to monitor health.
• Change fluid filters periodically (e.g., every 1000 hours or as per conditions).
• Check and replace worn or aged seals.
• Follow lubrication requirements for various points.
• Inspect the coupling for looseness or wear.

Primary reasons are:

• Insufficient Inflow: Caused by high suction line resistance, low oil level, excessive pump speed, or a clogged inlet strainer/suction line.
• Excessive Leakage: Worn internal parts (pistons, cylinder block, port plate) leading to high internal leakage.
• Swash Plate Angle: The swash plate angle might be set too small, minimizing displacement.

This is often due to the control mechanism being off its neutral point. The cause can be a misadjusted, loose, or damaged controller. The solution is to re-zero, tighten, or replace the controller.

Flow instability, often accompanied by pressure fluctuations, is frequently related to issues within the control piston mechanism. This can be due to contamination scratching the control piston, a weak or damaged control amplifier spring, or other damaged components. Addressing this usually requires disassembling the pump to inspect, repair, or replace the affected parts, and possibly increasing damping or spring stiffness.

External leaks can originate from:

• Shaft Seal: Damaged or worn-out shaft seal.
• Pipe Connections: Loose hose connections, damaged fittings, or aged/cracked sealing washers.
• Case Ports: Leaks from the variable mechanism cover bolts due to loose bolts or破损 seals.
• Case Imperfections: Rarely, sand holes in cast iron casings or poor welds.
• High Case Pressure: Excessive internal leakage can pressurize the case, damaging seals or pushing them out. Ensure the case drain line is unrestricted, of adequate size, and not too long.

Bearing flushing is recommended for: using special HF fluids, operating at viscosity/temperature limits, or for pumps installed vertically (shaft up). Refer to technical documentation for specific flow rates, which range from ~3 L/min for size 40 to ~40 L/min for size 1000.

If the pump is to be stored for an extended period:

• Drain all hydraulic fluid from the pump casing.
• Perform a thorough cleaning and drying.
• Apply a rust preventive agent.
• Store in a dry, ventilated place.
• Before putting back into service, perform a comprehensive inspection and maintenance check.