Technical Specifications & Performance Data
| Item | Specification / Value |
|---|---|
| COGENG Part Number | 707-99-85900 |
| OEM Reference | Komatsu Genuine 707-99-85900 |
| Application | Lift, Tilt, and Steering Cylinder Rebuild for Ultra-Class Loaders |
| Maximum System Pressure | 42 MPa (6,092 PSI) |
| Temperature Range (Continuous) | -30°C to +130°C |
| Primary Dynamic Seal Material | Reinforced Polyurethane (PU) |
| High-Temp/Static Seal Material | Fluorocarbon (FKM) |
| Wear Ring / Bearing Material | Carbon-Graphite Filled PTFE Composite |
| Wiper Material | Polyurethane (PU) with Metal Dust Exclusion Lip |
| Kit Inclusions | Complete set of piston seals, rod seals, multi-stage wipers, O-rings, anti-extrusion rings, heavy-duty wear bands, gland seals |
| Unit of Sale | Complete seal kit for one specified cylinder |
Component Specifications Table
| Component Name | Material | Hardness (Shore A) / Property | Quantity per Kit |
|---|---|---|---|
| Main Piston Seal (Step-Cut) | Reinforced Polyurethane (PU) | 94 ± 5 | 2 |
| Primary Rod Seal (U-Cup) | Reinforced Polyurethane (PU) | 92 ± 5 | 2 |
| Secondary Rod Seal (Glyd-Ring) | Fluorocarbon (FKM) | 80 ± 5 | 1 |
| Multi-Stage Wiper Assembly | PU (External) + NBR (Internal) | 95 ± 5 / 70 ± 5 | 1 Set |
| Static O-Ring (High-Pressure) | Fluorocarbon (FKM) | 75 ± 5 | 6-8 |
| Piston Wear Band (Heavy-Duty) | Carbon-Graphite Filled PTFE | Compressive Strength > 100 MPa | 2 |
| Rod Guide / Bearing Ring | Bronze-Filled PTFE Composite | Low Friction, High Load Capacity | 2 |
| Anti-Extrusion Backup Ring | Filled PTFE (Vespel-type) | High-Temp Stability | 4 |
| Cushion Seal (if applicable) | Polyurethane (PU) | 92 ± 5 | 1 |
Compatible Which models is it used for Models
| Compatible Model Series | Specific Compatible Models (Komatsu Ultra-Class Wheel Loaders) | Primary Cylinder Applications |
|---|---|---|
| WA800 Series | WA800-3, WA800L-3 | Main Lift Cylinders, Bucket Tilt Cylinders |
| WA900 Series | WA900-3, WA900L-3 | Main Lift Cylinders, Bucket Tilt Cylinders, Steering Cylinders (Variant Specific) |
| Note: | This kit is specifically designed for the large-bore hydraulic cylinders on the listed ultra-class loader models. Critical Verification: Compatibility is determined by the original Komatsu part number (707-99-85900). Always cross-reference your machine's model, serial number, and the specific cylinder assembly part number from the official Komatsu parts manual before purchase and installation. Use in incorrect cylinder models will result in seal failure. |
| NO | Number | Name | Qty |
| K | 707-99-85900 | SERVICE KIT | 2 |
| 707-01-03011 | CYLINDER ASS'Y,LIFT | 2 | |
| 707-01-02090 | |||
| 707-01-01010 | |||
| 707-01-07580 | |||
| 1 | 707-13-26013 | • CYLINDER | 1 |
| 2 | 707-76-18030 | • BUSHING | 1 |
| 3 | 707-27-26012 | • HEAD,CYLINDER | 1 |
| 4 | 707-52-11610 | • BUSHING | 1 |
| 5 | 707-51-16640 | • RING,BUFFER (KIT) | 1 |
| 6 | 707-51-16130 | • PACKING,ROD (KIT) | 1 |
| 7 | 566-63-22241 | • SEAL,DUST (KIT) | 1 |
| 8 | 07179-14180 | • RING,SNAP | 1 |
| 9 | 07000-15250 | • O-RING (KIT) | 1 |
| 10 | 707-35-92620 | • RING,BACK-UP (KIT) | 1 |
| 11 | 01011-63000 | • BOLT | 12 |
| 12 | 01643-33080 | • WASHER | 12 |
| 13 | 707-58-16070 | • ROD,PISTON | 1 |
| 14 | 707-76-18030 | • BUSHING | 1 |
| 15 | 07000-12135 | • O-RING (KIT) | 1 |
| 16 | 707-35-52880 | • RING,BACK-UP (KIT) | 2 |
| 17 | 707-36-26012 | • PISTON | 1 |
| 18 | 707-44-26180 | • RING,PISTON (KIT) | 1 |
| 19 | 707-39-26820 | • RING,WEAR (KIT) | 4 |
| 20 | 707-40-26011 | • SPACER | 2 |
| 21 | 01010-61665 | • BOLT | 6 |
Safety & Preparation: Park the loader on level ground, fully lower the bucket, and engage all safety locks. Relieve all hydraulic pressure and support the cylinder rod with appropriate equipment before disconnection.
Contamination Control: Due to the large size of these cylinders, perform disassembly and rebuild in the cleanest possible environment, ideally a positive-pressure clean room or enclosed shop area. Use protective caps on all openings immediately.
Detailed Inspection: Carefully inspect the cylinder barrel ID and piston rod OD for scoring, pitting, or thermal damage. Use precision measuring tools to check for ovality and wear beyond service limits outlined in the Komatsu service manual.
Seat & Groove Preparation: Deburr all seal groove edges with a fine stone. Clean grooves thoroughly with a solvent and lint-free cloth. Ensure all old seal material is completely removed.
Specialized Installation: Due to the large seal diameters, use specialized seal installation tools, cones, and heat boxes (for certain wear bands) as recommended. Never roll or stretch seals over sharp edges.
Post-Assembly Procedure: After reassembly, fill the cylinder slowly with filtered fluid and cycle it gently at low pressure to bleed air and seat the seals. Perform a phased pressure test before returning to full operational load.
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