YB60000254 Hitachi ZX330-5G hydraulic pump assembly HPV145 YB60000309

This high-precision heavy-duty hydraulic main pump assembly has core original part numbers and cross index numbers including YB60000253, YB60000254, YB60000309, and YB60000356. The core uses Hitachi's classic HPV145 series double high-pressure inclined disc piston pump. As the absolute power heart of the entire vehicle system, this assembly is specially designed for Hitachi's 5G series core excavators, perfectly matching the 33 to 35 ton core main models such as ZX330-5G and ZX350-5G. The product is based on first principles for ultra-high pressure fluid dynamics optimization design, deeply bearing heavy loads under frequent composite actions, ensuring absolute certainty of high flow power output. The physical dimensions of the product packaging are approximately 810mm × 440mm × 470mm, with an overall net weight of approximately 185kg. The original factory standard position is precisely aligned.

"Extreme cleaning and torque tightening: Dust removal treatment is required for unpacking and lifting environments. All high-pressure oil pipes and feedback signal pipes must be thoroughly cleaned with specialized cleaning agents before being connected to a new pump. Tighten bolts using torque wrenches strictly in accordance with the original factory standard torque for symmetrical and phased cross tightening, to prevent local stress deformation.

Forced oil injection (core pit avoidance): After the main pump is lifted into place and before starting the engine, clean hydraulic oil must be filled from the top oil injection/exhaust port of the main pump. It is strictly prohibited to start dry grinding, otherwise the internal rotating components will undergo irreversible physical erosion within 3 seconds of ignition.

Low pressure transition and exhaust: After the first ignition, the engine must be kept idling and running at low pressure for 10-15 minutes for automatic exhaust and thermodynamic adaptation of the system. The workload can only be gradually applied after the oil temperature and pressure are stable and the bubbles are cleared."