Hydraulic Cylinder Oil Seal Repair Kit

This hydraulic cylinder sealing kit is designed specifically for Komatsu PC300-7/-8, PC350-8, and PC360-7 excavators, and can directly replace the boom, stick, bucket, and adjust the cylinder. It aims to meet OEM specifications and solve common problems such as hydraulic leakage, cylinder drift, and weak digging ability caused by seal wear. This kit includes all the components required for a complete reconstruction, ensuring long-lasting performance in heavy-duty building environments.
Main oil seal (black/purple/blue)
Function: The core seal directly prevents high-pressure hydraulic oil from leaking from the inside of the cylinder and bears the main pressure of the system.
Characteristics: Different colors (such as NOK's purple, blue, and beige) usually represent different grades of polyurethane materials, with different high temperature resistance and wear resistance. Purple is mostly high-end high and low temperature resistant, while blue is heat-resistant.
Buffer oil seal (color version)
Function: Absorb the instantaneous pressure impact of the oil cylinder, protect the main oil seal from high pressure damage, and extend the service life of the main oil seal.
Dust seal (white/black)
Function: Installed on the outer side of the oil cylinder end cover, it prevents external dust, mud, and moisture from entering the interior of the oil cylinder and prevents the piston rod from being scratched.
Guidance ring/support ring (brown/beige)
Function: Support the piston rod/piston, prevent eccentric wear during movement, reduce the wear of seals, and improve the stability of oil cylinder operation.
O-ring (small black ring)
Function: As an auxiliary static seal, it fills the gaps between end caps, cylinder barrels, and other parts to prevent internal leakage
Very suitable for repairing hydraulic cylinders leaking on Komatsu PC300-7/-8, PC350-8, and PC360-7 excavators.
Restore full cylinder performance, eliminate drift, and ensure continuous excavation and power improvement.
Suitable for new and used excavators in construction, mining, and earthwork applications.