326-0502 Hydraulic Steering Cylinder Seal Kit 3260502 for Caterpillar CAT Wheel Loader 972H 972G 966G 966H Repair
326-0502 Hydraulic Steering Cylinder Seal Kit for Caterpillar 966G/966H/972G/972H Wheel Loaders – OEM-Compliant Steering System Repair
Product Overview
The 326-0502 Seal Kit is a Caterpillar-certified repair solution designed for the steering hydraulic cylinders of Cat 966G, 966H, 972G, and 972H wheel loaders. This kit restores precise steering control by sealing leaks in the articulation joint, ensuring safe operation in material handling, quarry, and construction environments.
Technical Specifications
| Parameter | Specification |
|---|---|
| Compatible Models | Cat 966G, 966H, 972G, 972H (S/N prefixes: D6N, M9J, etc.) |
| Application | Steering Cylinder Piston Seals, Rod Seals, and Articulation Joint Seals |
| Pressure Range | 0–22 MPa (3,190 PSI) – Matches Cat steering system design limits |
| Temperature Tolerance | -40°C to +110°C (-40°F to +230°F) |
| Primary Seal Material | Hydrogenated Nitrile (HNBR) – Resists oil degradation and wear |
| Secondary Seals | Fluorocarbon (FKM) Wiper Seals, PTFE Wear Rings, NBR O-Rings |
| Certifications | ISO 3601 (Hydraulic Seals), Caterpillar 1U-9901 Compliance |
Kit Components & Functions
| Component | Function |
|---|---|
| 1. Piston Seal (HNBR) | Double-acting U-cup maintains hydraulic pressure during steering articulation. |
| 2. Rod Seal (FKM) | Step-lip design prevents oil leakage along the cylinder rod. |
| 3. Articulation Joint Seal (HNBR) | Seals the pivot joint to prevent fluid loss and contamination. |
| 4. Dust Wiper (NBR) | Removes abrasive particles during rod retraction (ISO 10100 compliant). |
| 5. Wear Ring (PTFE) | Glass-reinforced PTFE reduces friction between piston and cylinder barrel. |
| 6. Buffer Seal (FKM) | Absorbs pressure spikes during abrupt steering maneuvers. |
| 7. O-Rings (HNBR) | High-pressure static seals for hydraulic port connections (SAE J1926). |
Key Features & Benefits
✅ OEM Precision Fit: Direct replacement for Cat part numbers 122-7980 and 223-9603.
✅ High Maneuverability: HNBR seals ensure smooth steering in high-cycle operations (500+ daily articulation cycles).
✅ Contamination Protection: Multi-layer wiper design exceeds ISO 4406 cleanliness standards.
✅ Extended Lifespan: PTFE wear rings reduce cylinder wear by 25% compared to non-OEM kits.
✅ Global Compliance: Adheres to EU Machinery Directive 2006/42/EC and REACH Regulation 1907/2006.
