707-98-36240 Bucket Cylinder Seal Kit for Komatsu PC128US-2

The 707-98-36240 Bucket Cylinder Seal Kit is an aftermarket replacement sealing kit for selected Komatsu excavator bucket hydraulic cylinders. It is referenced for the Komatsu PC128US-2 bucket cylinder assembly 203-63-02731.

This kit is used for hydraulic cylinder resealing during maintenance or overhaul. Reference dimensions for the applicable cylinder are a 65 mm piston rod diameter and a 95 mm cylinder bore. The cylinder assembly number and machine serial number should be confirmed before ordering.

707-98-36240 Bucket Cylinder Seal Kit Specifications

The dimensions listed above are application references. Actual seal profiles and component dimensions must match the original cylinder configuration.

Compatible Komatsu Bucket Cylinder Applications

The 707-98-36240 repair kit is associated with selected Komatsu excavator bucket cylinder applications.

• Komatsu PC128US-2: Bucket cylinder 203-63-02731, S/N 5001-UP.

• Komatsu PC130-6: Selected bucket cylinder assemblies 203-63-02731 and 203-63-07730.

• Komatsu PC120-6: Selected bucket cylinder configurations, subject to verification.

Compatibility should be confirmed using the original cylinder assembly number rather than the excavator model alone. Different machine generations may use different sealing arrangements.

Bucket Cylinder Seal Kit Components

Hydraulic bucket cylinder repair kits contain sealing components designed to maintain hydraulic pressure and limit leakage and contamination.

Depending on the supplied kit specification, components may include:

• Rod seals for hydraulic fluid retention around the piston rod.

• Buffer seals supporting the primary rod sealing system.

• Piston seals separating the hydraulic pressure chambers.

• Dust wipers limiting external contamination.

• O-rings and back-up rings for applicable sealing grooves.

• Wear rings and guide components where specified by the cylinder design.

The exact quantity, profile and material of each sealing component should be verified against the actual kit specification before purchase.

Bucket Cylinder Inspection and Replacement

Bucket cylinder sealing components should be inspected when external oil leakage, hydraulic cylinder drift or abnormal bucket operation is observed. These symptoms may also result from other hydraulic or mechanical problems.

During cylinder servicing, check:

• Piston rod condition, including scoring and corrosion.

• Cylinder barrel wear and internal damage.

• Rod seal and piston seal grooves.

• Cylinder head, guide and wear surfaces.

• Hydraulic oil cleanliness.

• Seal orientation and installation condition.

Release hydraulic pressure safely before disassembly and follow the applicable Komatsu service procedure. Damaged cylinder components should be repaired before new seals are installed.