YB00004816 Genuine Hitachi hydraulic pump repair kit for Hitachi excavators ZX330-5A and ZX330-5G.

Part No. YB00004816 is a dedicated overhaul kit for the HPV145 dual variable displacement axial piston pump of Hitachi ZX330-5A/5G excavators. It is compatible with ZX330-3/3G, ZX350-5A/5G and other models on the same platform, matching the Isuzu 6HK1 engine and HIOS III hydraulic system. The kit is suitable for a single pump displacement of 145cc/rev, with a main pump rated pressure of 31.4MPa and a maximum pressure resistance of 34.3MPa. The maximum combined flow rate of the dual pumps is 2×290L/min, the drive shaft spline has 17 teeth, and it is applicable to an oil temperature range of -20℃ to 80℃. Designed specifically for mining, heavy-duty crushing and other working conditions, it ensures efficient and stable operation of the hydraulic system.

Before maintenance, disconnect the negative battery terminal, loosen the main pump oil outlet bolt to release residual pressure, then mark the oil pipe interfaces and coupling alignment marks. Remove the pump body fixing bolts with a torque of 180-210N·m, lift the pump body off and disassemble the variable mechanism, end cover, piston shoe assembly, cylinder block, valve plate and other components in sequence. After cleaning, inspect the wear of parts and replace over-tolerance components with new ones from the kit. Assemble new seals coated with hydraulic oil, align the coupling marks and tighten the bolts, fill with ISO VG46 anti-wear hydraulic oil. After an idle test run with no leakage or abnormal noise, adjust the main relief valve pressure to 31.4MPa before putting it into service.

This kit can directly replace the core worn components of the hydraulic pump without replacing the entire pump, reducing maintenance costs by more than 60%. After replacement, the pump performance is restored to 97% of the original factory standard, improving the overall machine operation efficiency by 22% and reducing the hydraulic failure downtime rate by 35%. The kit components feature a dimensional accuracy of ±0.02mm and are made of high-strength wear-resistant alloy materials, suitable for dusty, vibrating and heavy-duty construction environments. It extends the secondary service life of the hydraulic pump to 9000 hours, cuts fuel consumption by 9%, and significantly reduces the overall equipment operation and maintenance costs.