6524032180 Original Loader Back-up Ring for ZW370 ZW550 

Part number 6524032180 is a specialized part number for the support ring of Hitachi's original loader. The support ring (also known as the guide ring or wear-resistant ring) is one of the core components of hydraulic cylinders, mainly installed on the piston or piston rod, playing a supporting and guiding role, preventing direct metal contact between the piston/piston rod and the cylinder barrel, thereby avoiding pulling and eccentric wear, and bearing lateral loads, ensuring smooth operation of the cylinder. As a standard component of the original factory, it is usually compatible with hydraulic cylinders such as boom, bucket, and steering of multiple wheel loaders in Hitachi ZW series. Common models include ZW180, ZW220, ZW250, ZW310, ZW370, etc.

This support ring is a key guiding and load-bearing component inside the hydraulic cylinder. Its core function is to provide radial support for the piston or piston rod during the reciprocating motion of the oil cylinder, guide it to move in a straight line along the axis, prevent direct friction, jamming, and abnormal wear between metals caused by lateral forces, and protect the main seals (such as piston seals and piston rod seals) from eccentric compression, extending the service life of the entire sealing system. It can withstand working pressures of up to 25-31.5MPa in the hydraulic system of the loader and a wide temperature range of -40 ℃ to 120 ℃, ensuring dimensional stability and reliable performance under frequent start stop and load fluctuations.

The maintenance core of this support ring lies in regular inspection, preventive replacement, and standardized installation. The support ring is a worn part, and it is usually recommended to perform preventive replacement simultaneously during major repairs or replacement of the main seal of the oil cylinder. If the inspection finds that the wear of the ring body exceeds the standard, there are obvious scratches on the surface, or it has lost elasticity, it should be replaced immediately. The lifespan of the support ring is closely related to the cleanliness of the hydraulic oil. It is necessary to strictly follow the maintenance cycle to replace hydraulic oil and filter elements, keep the system clean, and prevent hard particle pollutants from accelerating the wear of the support ring.