XP00000462 Genuine Hitachi O-rings in original packaging for Hitachi ZX450-3 excavators.

Part number XP00000462 is a dedicated O - ring seal kit for the overhaul of the main control valve (MCV) of Hitachi ZX450-3/ZX450LC-3 excavators. It is compatible with the main control valves of large Zaxis - 3 series excavators such as ZX450-3/ZX450LC-3 and ZX470-3, as well as models with the same main control valve like ZX450H-3/ZX450K-3. It is suitable for the high - pressure hydraulic system (rated pressure 31.5MPa) of the Isuzu 6HK1 engine. Made of a combination of NBR nitrile rubber (oil - resistant, temperature - resistant from - 30℃ to 120℃, suitable for low - medium pressure oil circuits) and FKM fluororubber (high - pressure resistant, chemical - resistant, suitable for high - pressure oil circuits), the kit contains 180-220 O - rings of different specifications (including standard, thickened and dust - proof types), covering key sealing parts of the main control valve such as the valve cover, valve stem, oil port and pilot interface, ensuring the oil circuit sealing and pressure stability of the main control valve and preventing oil leakage and pressure loss.

Its core function is to replace all O - rings during the overhaul of the main control valve, preventing internal and external leakage at parts such as the valve cover, valve stem and oil port, maintaining the pressure stability of the hydraulic system, and reducing failures such as valve stem jamming, slow movement and power loss caused by seal failure. The O - rings have a dimensional accuracy of ±0.05mm, a hardness of 70±5 Shore A, a tensile strength of ≥18MPa and an elongation at break of ≥300%. They are suitable for the working conditions of heavy - duty excavators with heavy dust, vibration and large temperature differences. The average service life is ≥8000 hours, ensuring the long - term and efficient operation of the main control valve and reducing hydraulic oil consumption and environmental pollution.

Before replacement, release the pressure of the hydraulic system. When disassembling the main control valve, remove the fixing bolts with a torque of 8-10N·m and clean the valve seat and sealing groove (free of burrs, oil stains and impurities). When installing, apply special hydraulic oil to the O - rings (do not use grease), install them according to the corresponding specifications, and tighten the bolts symmetrically (torque 8-10N·m). After installation, conduct a pressure test at 31.5MPa (no leakage) and check the flexibility of the valve core movement. This seal kit can reduce the leakage failure rate of the main control valve by more than 90%, reduce hydraulic oil loss by 40%, increase the response speed of the hydraulic system by 15%, extend the service life of the main control valve and hydraulic components, and reduce maintenance costs and downtime.