338-7038 Hydraulic Cylinder Seal Kit 3387038 for Caterpillar Backhoe Loader CAT 416E 416F 420E 420F
338-7038 Hydraulic Cylinder Seal Kit for Caterpillar® 416E/416F/420E/420F Backhoe Loaders – OEM-Certified Repair Solution
Product Overview
The 338-7038 Seal Kit is a Caterpillar-approved repair solution designed for the hydraulic cylinders of Cat 416E, 416F, 420E, and 420F backhoe loaders. This kit provides a complete sealing system for boom, arm, and bucket cylinders, ensuring leak-free operation and precise control in excavation, trenching, and material handling tasks.
Technical Specifications
| Parameter | Specification |
|---|---|
| Compatible Models | Cat 416E, 416F, 420E, 420F (S/N prefixes: FBP, JDP, etc.) |
| Application | Hydraulic Cylinder Piston Seals, Rod Seals, Dust Wipers |
| Pressure Range | 0–25 MPa (3,626 PSI) – Matches Cat hydraulic system design |
| Temperature Tolerance | -30°C to +110°C (-22°F to +230°F) |
| Primary Seal Material | Hydrogenated Nitrile (HNBR) – Resists oil degradation and abrasive wear |
| Secondary Seals | Fluorocarbon (FKM) Wiper Seals, PTFE Wear Rings, NBR O-Rings |
| Certifications | ISO 6194 (Rotary Shaft Seals), Caterpillar 5P-1960 Compliance |
Kit Components & Functions
| Component | Function |
|---|---|
| 1. Piston Seal (HNBR) | Dual-acting U-cup maintains hydraulic pressure during dynamic digging loads. |
| 2. Rod Seal (FKM) | Step-lip design prevents oil leakage along the cylinder rod. |
| 3. Dust Wiper (NBR) | Removes debris during rod retraction (ISO 10100 compliant). |
| 4. Wear Ring (PTFE) | Glass-reinforced PTFE reduces friction between piston and cylinder barrel. |
| 5. Buffer Seal (FKM) | Absorbs pressure spikes during abrupt load changes. |
| 6. O-Rings (HNBR) | High-pressure static seals for hydraulic port connections (SAE J1926). |
| 7. Backup Ring (PU) | Reinforces rod seal against extrusion under side loads. |
Key Features & Benefits
✅ OEM Precision Fit: Direct replacement for Cat part numbers 122-8012 and 223-9550.
✅ High-Cycle Performance: HNBR seals withstand over 450,000 cycles in heavy-duty operations.
✅ Contamination Defense: Multi-layer wiper design exceeds ISO 4406 cleanliness standards.
✅ Extended Lifespan: PTFE wear rings reduce cylinder wear by 30% compared to standard kits.
✅ Global Compliance: Adheres to EU Machinery Directive 2006/42/EC and REACH Regulation 1907/2006.
