9255402 Original Hydraulic Pump for ZW310

The original hydraulic pump assembly 9255402 (also commonly labeled as 263J712021 or 263J7-12022) is the core hydraulic power component of the Hitachi ZW310 wheel loader (with a total operating weight of approximately 22280kg and a rated load capacity of 8000kg). This pump is designed specifically for the ZW310 series and is fully compatible with models of different generations and configurations such as ZW310-5, ZW310-6, ZW310-7, etc. Its installation flange, shaft extension size, inlet and outlet positions, and control oil ports are all accurately matched with the hydraulic system of ZW310 (using a variable inclined shaft plunger pump), ensuring that there is no need to modify pipelines or brackets when directly replacing. When placing an order, it is necessary to verify the factory number of the host and the part number on the pump body label to avoid confusion with domestic counterfeit parts.

This product is a variable displacement inclined shaft axial piston pump, which is the main pump of ZW310 hydraulic system. Its rated working pressure is usually between 30-35MPa (about 300-350bar), and the maximum instantaneous pressure can reach over 40MPa. The estimated displacement is in the range of 180-250cc/rev, to meet the high load action requirements such as boom lifting and bucket flipping under the 220kW engine power of the whole machine. The pump body is made of high-strength cast iron, and the surfaces of key friction pairs such as the plunger, slide shoe, and distribution plate are ultra precision ground and coated with hard chromium or ceramic coating, which has excellent wear resistance and impact resistance. Equipped with intelligent control valves such as pressure cutoff, load sensitivity, and power limitation, it can automatically adjust flow and pressure according to working conditions, achieving high efficiency and energy saving. The original pump has undergone strict bench durability and pulse testing to ensure long-term reliable operation within the oil temperature range of -25 ℃ to 90 ℃.

Check the pump body for abnormal vibration, noise, and leakage every 500 hours of daily work. Replace the hydraulic oil and oil suction and return filter elements every 1000 hours or annually (it is recommended to use anti-wear hydraulic oil with the specified viscosity grade from the original factory). It is strictly prohibited to operate the pump in a state of no oil or excessive oil contamination (NAS level 9 or below). If the system pressure is insufficient or the action is slow, the pilot pressure, control valve, and relief valve should be checked first. Non professionals should not adjust the internal pressure setting screw of the pump without authorization. The overhaul cycle is usually 8000-10000 working hours, and it needs to be professionally repaired by authorized service providers using original repair kits (including plungers, distribution plates, seals, etc.). Long term shutdown should start the engine every month to allow the hydraulic pump to run for a short period of time to prevent internal corrosion.