707-99-67090 Excavator Arm Cylinder Seal Kit for Komatsu PC300-7
Excavator Arm Cylinder Seal Kit Product Overview
The 707-99-67090 Seal Kit is engineered exclusively for Komatsu PC300-7 /8 and PC300LC-7 /8 excavators hydraulic arm (stick) cylinders repair. This OE-equivalent solution restores critical hydraulic sealing to prevent pressure loss during heavy digging and lifting operations.
707-99-67090 Seal Kit Technical Specifications
| Komatsu Models | PC300-7 / 8, PC300LC-7 / 8 (Arm Cylinder Repair Kit) |
| Cylinder Dimensions | Rod: 105mm (4.13″) |
| Operating Pressure | 34.3 MPa (4,975 PSI) w/ 40MPa Peak Tolerance – Meets Komatsu Standards |
| Temperature Range | -40°C to +120°C (-40°F to +248°F) – depends on the material, Support custom |
| Seal Materials | Primary Seals: Cast Polyurethane (Grade 5AU) |
| Critical Components | HNBR O-Rings, Anti-Extrusion Washers (Bronze-Filled PTFE), Purple Polyurethane Wiper |
| Compatibility | Fluids: Komatsu BIO HF-2/HF-3, KES 07.881 Mineral Oils |
The Excavator Arm Seal Kit Main Components
| Pressure-Actuated U-Cups Seal | Double-lip directional design resorts seal extrusion at rod angles >8° |
| Load-Bearing Buffer Rings | PTFE composite prevents U-cup damage under 140MPa localized stress |
| Multi-Stage Wiper | Purple polyurethane triple-lobe design excludes abrasive particles >15 microns |
| Rod Guide Band | Sintered bronze with PTFE coating minimizes friction-induced scoring |
| HNBR Seals | Bio-oil resistant (SAE J200 Type CH) for PC300-7’s closed-loop hydraulic circuit |
| Anti-Wear Rings | Prevents gland wear during cylinder misalignment |
707-99-67090 Arm Seal Kits Key Features
✅ Standard or OEM: Direct replacement for Komatsu PC300-7 / 8, PC300LC-7 / 8 excavators arm cylinders repair
✅ Heavy-Duty Pressure Handling: 34.3MPa dynamic rating exceeds PC300-7 operating specs
✅ Impact & Vibration Resistance: Polyurethane seals absorb shock loads during rock digging
✅ Abrasion Defense: Wiper lifespan 2.5x rubber seals in slurry environments
✅ -40°C Low-Temp Flexibility: Eliminates brittle fractures in Arctic operations
✅ Corrosion Protection: HNBR compounds resist acidic hydraulic fluid breakdown
Frequently Asked Questions (FAQ)
Q: Do you have any other excavator model repair seal kits ?
A: Yes. As the professional excavator seal kits manufacturer, we produce all the excavators repair seal kits, standard sizes and also support customization. Please tell us the part number seal kit you want.
Q: I can’t find the model I want. Are all your seal repair kits here?
A: No. We have more than tens of thousands seal kits. Here only a small part of them is shown. We have stock of all the seal kits for construction machinery. Please contact us!
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Contact Us
For more information or to request a quote, please contact us or email [email protected].
