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CAT 4557978 (455-7978 ) Piston Pump | Fits 434F2 427F2 428F2

CAT 4557978 (455-7978 ) Piston Pump | Fits 434F2 427F2 428F2

Premium hydraulic piston pump designed as a direct OEM-compatible replacement for Caterpillar 434F2, 427F2, and 428F2 backhoe loaders. Built to deliver reliable hydraulic flow, high-pressure efficiency, and extended service life in demanding digging, loading, and construction applications.

Product Highlights

  • Part Number: 4557978 / 455-7978
  • Direct Fit OEM Replacement: Form, fit, and function match original Caterpillar specifications perfectly without modifications.
  • Heavy-Duty Construction: Engineered with premium-grade materials and advanced rotating groups to withstand extreme hydraulic pressures and continuous workloads.
  • Optimized Efficiency: Precision-machined pistons and valve plates ensure high volumetric efficiency and consistent hydraulic power to the loader and backhoe implement systems.

Technical Specifications

Parameter Specification
Part Number 4557978 / 455-7978
Product Type Heavy-Duty Hydraulic Piston Pump
Brand Compatibility Caterpillar (CAT)
Application Main Hydraulic & Implement System
Material High-Strength Cast Iron / Precision Alloys
Warranty 12 Months Warranty

Compatible Models & Equipment

This premium piston pump is precision-engineered to fit the following Caterpillar heavy equipment:

Backhoe Loaders

  • Caterpillar 427F2 Backhoe Loader
  • Caterpillar 428F2 Backhoe Loader
  • Caterpillar 434F2 Backhoe Loader

Key Applications

  • Backhoe & Loader Hydraulics: Powers core machine operations, including front loader bucket lifting/tilting and rear backhoe digging/booming functions.
  • Heavy Construction & Excavation: Engineered for continuous high-load operations in utility trenching, infrastructure, and material handling.
  • System Pressure Maintenance: Restores original hydraulic pressure and swift cycle times to your CAT backhoe loader's hydraulic circuits.

Why Choose Our Aftermarket CAT Pumps?

  • Guaranteed OEM Quality: Manufactured under strict ISO 9001 quality standards to meet or exceed original equipment performance.
  • Cost-Effective Solution: Get dealer-level reliability and performance at a fraction of the OEM price.
  • Ready to Ship: Maintained in stock for immediate worldwide dispatch to minimize your machine's downtime.
  • Industry-Leading Support: Backed by a full 1-year warranty and a team of dedicated heavy equipment hydraulic experts.

Frequently Asked Questions (FAQ)

Q: Is this piston pump a genuine Caterpillar part?

A: This is a premium-grade, OEM-compatible aftermarket replacement pump. It is designed to exact CAT engineering dimensions and standards, serving as a direct drop-in replacement for part number 455-7978.

Q: What is covered under the 12-month warranty?

A: Our 12-month warranty covers all manufacturing defects, material failures, and workmanship issues under normal operating conditions.

Q: Does this pump include the necessary seals or O-rings for installation?

A: The pump comes ready for installation. For specific sealing kits or complementary gaskets, please contact our support team during inquiry.

Q: How long does shipping take?

A: Standard in-stock orders typically ship within 3–5 business days. We also offer expedited and air freight shipping options for urgent breakdown situations.


Explore our full range of heavy-duty hydraulic pumps:
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