Swing Hydraulic Pump Assembly 266-7953 259-0784 for E385C E390D Excavator

This swing hydraulic pump assembly, with part numbers 266-7953 and 259-0784, is the hydraulic power unit specially designed for the swing system of E385C and E390D excavators. It supplies high-pressure hydraulic oil to drive the swing motor assembly.

The unit adopts a variable piston structure with precise flow control, wear-resistant alloy materials, and precision machining. It is designed for direct replacement installation and delivers stable output performance under heavy-duty mining and construction working conditions.

• Internal piston and valve plate wear, causing pressure drop and weak swing action
• Internal seal failure resulting in hydraulic oil leakage
• Abnormal noise and vibration during operation
• Servo piston stuck, leading to flow adjustment failure
• Housing cracks caused by overload and high pressure

• Confirm the part number and machine serial number before ordering
• Check spline specification, mounting dimension, and control type
• Request strict pressure and performance testing before shipment
• Shockproof wooden packaging to avoid transit damage
• Quality warranty covering manufacturing defects