4477852 Original Excavator Oil Seal for ZX330

The part number is 4477852, which is the original standard oil seal specially designed by Hitachi for the ZX330 series medium-sized hydraulic excavator. Its universal model is this part number, which is usually used for key parts such as piston rod seals, dust seals for various valve stems, or auxiliary seals for rotating shafts in hydraulic cylinders of this model (such as buckets, arm cylinders, and boom cylinders). As an original precision dynamic seal, its inner diameter, outer diameter, and thickness are perfectly matched with the corresponding shaft diameter and sealing installation groove. It is strictly prohibited to use universal oil seals that do not match the size or material to replace them, in order to avoid oil leakage, dust intrusion, or early sealing failure.

This product is an oil seal with a sturdy metal frame on the outside, providing installation rigidity and support; Internally, there is a nitrile rubber sealing lip with a self tightening spring, which is responsible for tightly contacting the rotating shaft surface and achieving dynamic sealing. The central hole visible in the picture is its working inner diameter. Its material is specially designed to withstand hydraulic oil, lubricating oil, and certain mud and water splashing environments. The working pressure is usually low or normal pressure, and the working temperature range is -30 ℃ to+120 ℃. It is the basic seal to prevent lubricant leakage, protect bearings and motion pairs.

Installation specifications: 1 Cleaning: Before installation, the shaft neck, oil seal installation hole, and the new oil seal itself must be thoroughly cleaned with a lint free cloth and cleaning agent to ensure that there are no burrs or impurities. 2. Lubrication: Apply a layer of lubricating grease that is compatible with the system evenly on the sealing lip and inner hole of the oil seal. 3. Positive pressing: A dedicated installation sleeve or a suitable size core shaft must be used to ensure that the oil seal is absolutely vertical and smoothly pressed into the installation hole until it is in place. It is strictly prohibited to directly strike the edge of the oil seal with a hammer to avoid deformation and seal failure.