Rexroth A4VSO250 Hydraulic Piston Pump 250cc Flange Mount

• Keep the pump exterior clean from dust and oil
• Check oil levels before start-up and during operation
• Listen for abnormal noises during operation
• Regularly record operating parameters (pressure, flow, temperature)
• Change fluid filters periodically (every 1000 hours or as needed)
• Check and replace worn or aged seals
• Follow lubrication requirements
• Inspect the coupling for looseness or wear

Possible causes:

• Insufficient inflow due to high suction line resistance, low oil level, excessive pump speed, or clogged inlet
• Excessive leakage from worn internal parts (pistons, cylinder block, port plate)
• Swash plate angle set too small

Typically caused by control mechanism being off its neutral point due to misadjustment, looseness, or damage. Solution involves re-zeroing, tightening, or replacing the controller.

Often related to control piston mechanism issues caused by contamination, weak/damaged control amplifier spring, or other damaged components. Requires disassembly for inspection and possible part replacement.

Potential leak sources:

• Shaft seal damage or wear
• Loose hose connections or damaged fittings
• Leaks from variable mechanism cover bolts
• Case imperfections (rare)
• High case pressure from excessive internal leakage