| Parameter | Value / Specification |
|---|---|
| Maximum Operating Pressure | Up to 4,350 PSI (300 bar) |
| Temperature Range | -40°F to 225°F (-40°C to 107°C) |
| Fluid Compatibility | Mineral-based hydraulic oils, Komatsu Super Hydraulic Fluid (KSHV), BIO HFDU fluids |
| Primary Seal Material | Polyurethane (AU) & Nitrile Rubber (NBR) |
| Seal Hardness (Dynamic) | 90-94 Shore A (Polyurethane) |
| Seal Hardness (Static) | 70 Shore A (NBR O-Rings) |
| Design Standard | Engineered to meet or exceed Komatsu's original specifications for pressure holding, wear resistance, and service life. |
| Komatsu Equipment Model | Specific Application |
|---|---|
| Komatsu D65EX/PX-12, D65EX/PX-15 | Blade Lift (Hoist) Cylinders |
| Komatsu D85EX/PX-15 | Blade Lift (Hoist) Cylinders |
| Note: | This kit is a direct replacement for Komatsu OEM part number 707-98-05460. It is designed specifically for the LIFT/HOIST CYLINDERS on the listed bulldozer models. It is critical to verify your machine model, serial number, and that you are servicing the BLADE LIFT CYLINDERS, not the tilt or pitch cylinders. |
| Component Name | Material | Color | Durometer | Function |
|---|---|---|---|---|
| Main Piston Seal (U-Cup) | Polyurethane (AU) | Brown | 94 Shore A | Primary high-pressure dynamic seal on piston |
| Rod Seal (Step Seal) | Cast Polyurethane (CU) | Black | 92 Shore A | Main rod seal for pressure retention |
| Wiper/Scraper (Heavy-Duty) | Polyurethane (PU) | Black | 90 Shore A | Excludes abrasive dirt, mud, and debris |
| Buffer Ring | Polyurethane (CU) | Black | 90 Shore A | Dampens pressure spikes to protect rod seal |
| O-Ring Kit (Assorted) | Nitrile Rubber (NBR) | Black | 70 Shore A | Static sealing for gland, end cap, and ports |
| Wear Ring / Guide Band | Glass-Filled PTFE | Dark Brown | N/A | Centralizes piston, prevents metal contact |
| Backup Rings | Nylon 6.6 | Tan | N/A | Prevents extrusion of static O-rings under extreme pressure |
Safe Depressurization & Support: Park the machine on level ground. Lower all attachments (bucket, stabilizers, backhoe) to the ground to relieve hydraulic pressure.
Clean Workspace: Perform all work in a meticulously clean environment to prevent contamination of the hydraulic system.
Documented Disassembly: Carefully disassemble the cylinder. Photograph and label each component and its orientation.
Mandatory Metal Inspection: Thoroughly inspect the cylinder rod for scratches, pitting, or scoring. Inspect the cylinder bore for wear or damage. Replace any damaged metal components before installing new seals.
Proper Seal Installation: Lubricate all new seals with clean hydraulic fluid. Use seal installation tools (cone tools, sleeves) to guide seals over threads and sharp edges without damage.
Precision Reassembly: Follow the included diagram for correct seal order and orientation. Ensure all seals are fully seated in their grooves.
Torque Specifications: Use a calibrated torque wrench. Adhere strictly to Komatsu's specified torque values and sequences for all fasteners (gland bolts, tie-rods)
