The YNF16839 (4640118) Arm Cylinder Seal Kit and DU Bush is designed for Hitachi ZX330-1 excavators, offering a complete sealing and bushing solution for the arm (middle boom) hydraulic cylinder. Built with high-quality rubber materials, precision PTFE components, and durable DU bushings, this kit ensures leak-free cylinder performance, smooth arm movement, and extended service life in demanding work environments.

• Compatible with Hitachi ZX330-1 excavators

• Direct replacement for OEM part number 4640118

• Includes a full set of seals, O-rings, wear rings, and durable DU bushes for complete arm cylinder maintenance

• Manufactured using premium NBR, PU, PTFE materials and high-wear DU bushings

• Ensures stable, leak-free operation of the arm (middle boom) hydraulic cylinder

• OEM-standard dimensions for precise fitment and easy installation

• Suitable for preventive maintenance or full hydraulic cylinder overhaul

• Enhances the durability and performance of the arm cylinder under heavy-duty conditions

• Machine model: Hitachi ZX330-1

• Component: Arm (Middle Boom) Hydraulic Cylinder

• Suitable for construction, mining, demolition, and heavy-duty earthmoving operations

• Technical support and installation guidance

• Pre-shipment photo confirmation

• Long-term stable supply for wholesalers and repair service providers

• Custom seal kit and DU bush solutions available upon request

• Individual seals and DU bushes packed for protection

• Export-grade carton packaging

• YNF branded or neutral packaging options available

Q1: Does this kit fit other Hitachi machines?
A: It is designed specifically for ZX330-1. Please send your OEM number or part photos for cross-checking.

Q2: How long do the seals and bushes last?
A: Typically 12–24 months, depending on working conditions and maintenance quality.

Q3: Can I combine this with other seal kits in one shipment?
A: Yes, mixed orders are fully supported.