- CN
| Parameter | Specification / Value |
|---|---|
| COGENG Part Number | 707-99-34300K |
| Compatible OEM Number | 707-99-34300 (Komatsu) |
| Primary Seal Material | Hydrogenated Nitrile Rubber (HNBR) |
| Temperature Range | -35°C to +120°C (-31°F to +248°F) |
| Pressure Rating (Max) | 45 MPa (6,500 psi) |
| Fluid Compatibility | Standard Mineral-based Hydraulic Oils, Biodegradable Fluids, Water Glycol |
| Storage Life | 5 years in original packaging under cool, dry conditions |
| Component Name | Material | Quantity per Kit | Key Function |
|---|---|---|---|
| Main Piston Seal | Polyurethane (PU) | 1 | Primary high-pressure sealing for piston. |
| Rod Seal | HNBR with PTFE backing | 1 | Primary dynamic seal for the rod. |
| Buffer Seal | HNBR | 1 | Protects rod seal from pressure spikes. |
| Wiper / Scraper | Polyurethane (PU) | 1 | Excludes external contaminants. |
| Piston Wear Band (Guide Ring) | PTFE Composite | 2 | Guides piston, prevents metal-to-metal contact. |
| Rod Wear Band (Guide Ring) | PTFE Composite | 1 | Guides rod, ensures smooth movement. |
| O-Rings (Various) | HNBR / NBR | As required | Static sealing for gland, ports, etc. |
| Back-up Rings | PTFE / Nylon | As required | Prevents extrusion of seals under high pressure. |
This seal kit is designed for use on specific cylinders of the following Komatsu excavator models. Always verify the cylinder assembly number before installation.
| Model Series | Specific Models | Typical Application Cylinder |
|---|---|---|
| PC200/220 | PC200-6, PC200-7, PC200-8, PC220-6, PC220-7, PC220-8 | Boom, Arm, or Bucket Cylinder |
| PC300/350 | PC300-6, PC300-7, PC350-6, PC350-7, PC350-8 | Arm or Bucket Cylinder |
| PC400 | PC400-6, PC400-7 | Bucket Cylinder |
| PC130/138US | PC130-7, PC138US-10 | Boom or Arm Cylinder |
Safety First: Depressurize the hydraulic system completely. Securely block the machine and cylinder to prevent any accidental movement.
Clean Environment: Perform disassembly and assembly in a clean, dust-free area to prevent contamination.
Careful Disassembly: Mark components for reassembly. Use proper tools to avoid scratching or damaging the cylinder tube, rod, and gland surfaces.
Inspection: Thoroughly clean and inspect all metal components (piston, rod, tube bore, gland) for scoring, pitting, or wear. Replace any damaged components.
Seal Installation:
Lubricate all seals and components with clean hydraulic fluid or specified grease during assembly.
Use installation sleeves or tape to protect seals from sharp edges and threads.
Ensure seals are not twisted, cut, or over-stretched. Install them in the correct orientation as indicated in the kit diagram.
Deburring: Remove all burrs and sharp edges from components before fitting new seals.
Post-Installation: After reassembly, bleed the cylinder of air by cycling it slowly several times before returning to full operation. Check for leaks initially and monitor after the first few hours of operation.
