397-5704 Hydraulic Boom Cylinder Seal Kit 3975704 for Caterpillar CAT Backhoe Loader 416E 416F 420E 430E 420F 430F 432E 434E
397-5704 Hydraulic Boom Cylinder Seal Kit for Caterpillar 416E/416F/420F/430F Backhoe Loaders – OEM-Compliant Repair Solution
Product Overview
The 397-5704 Seal Kit is a Caterpillar-certified repair solution designed for the boom hydraulic cylinders of Cat 416E, 416F, 420E, 420F, 430E, 430F, 432E, and 434E backhoe loaders. This kit restores factory sealing performance to eliminate leaks, ensure precise boom control, and extend cylinder lifespan in heavy-duty excavation and trenching applications.
Technical Specifications
| Parameter | Specification |
|---|---|
| Compatible Models | Cat 416E, 416F, 420E, 420F, 430E, 430F, 432E, 434E |
| Application | Boom Cylinder Piston Seals, Rod Seals, and Dust Wipers |
| Pressure Range | 0–25 MPa (3,626 PSI) – Matches Cat hydraulic system standards |
| 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 boom lifting/digging. |
| 2. Rod Seal (FKM) | Step-lip design prevents oil leakage along the cylinder rod. |
| 3. Dust Wiper (NBR) | Removes debris from the rod surface during retraction (ISO 10100 compliant). |
| 4. Wear Ring (PTFE) | Glass-reinforced PTFE reduces friction between piston and cylinder barrel. |
| 5. Buffer Seal (FKM) | Secondary seal 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 side-load extrusion in uneven terrain. |
Key Features & Benefits
✅ OEM Interchangeability: Direct replacement for Cat part numbers 122-8095 and 223-9750.
✅ Extended Durability: HNBR seals withstand over 400,000 cycles in high-load trenching operations.
✅ Contamination Resistance: Multi-layer wiper design exceeds ISO 4406 cleanliness standards.
✅ Cost Efficiency: Reduces downtime by 40% compared to non-OEM alternatives (field-tested).
✅ Global Compliance: Adheres to EU Machinery Directive 2006/42/EC and RoHS Directive 2011/65/EU.
