John Deere AT444573 AT457670 Hydraulic Pump | 83032678 83041431 | Piston Pump for Feller Bunchers

LIC Hydraulic offers premium AT444573 and AT457670 axial piston variable displacement pumps, specifically engineered for John Deere and Hitachi heavy forestry machinery. These units are the primary power source for Feller Bunchers, designed to endure the high-pressure spikes and relentless duty cycles of timber harvesting. Our units provide 100% seamless interchangeability with OEM parts 83032678 and 83041431. Each pump is subjected to 100% full-load simulated testing to ensure it meets the rigorous volumetric and mechanical standards required for John Deere 900-series chassis.

Technical Specifications

• John Deere Part Numbers: AT444573, AT457670

• Hitachi/OEM Part Numbers: 83032678, 83041431

• Design Architecture: Based on High-Pressure Rexroth Series

• Rated Pressure: 350 bar (5075 psi)

• Peak Pressure: 400 bar (5800 psi)

• Control Type: Load Sensing (LS), Pressure Limiter (DR), and Power Control (LR)

• Max Speed: Up to 2600 rpm

• Housing: Reinforced Ductile Iron for high vibration resistance

• Seals: High-temp Viton for superior fluid compatibility

Key Technical Advantages

• Forestry-Toughened Internals: Optimized for felling heads and boom movements. The rotating groups undergo advanced nitriding to resist adhesive wear during rapid load fluctuations.

• Ultra-Fast Control Response: The integrated compensator precisely matches flow to demand, preventing excessive heat generation during high-cycle logging operations.

• High Volumetric Integrity: Utilizing precision-lapped valve plates and spherical piston technology, our pumps maintain maximum efficiency even at 350 bar, ensuring no loss in cycle times.

• Full Through-Drive Capability: Pre-configured for tandem mounting of auxiliary pumps, allowing for a compact and integrated hydraulic layout on the engine drive.

Application Areas

• John Deere Feller Bunchers: Primary hydraulics for models 903K, 903L, 909K, 909L, 953K, 953L, 959K, 959L.

• Hitachi Forestry Machinery: Hitachi excavators and harvesters utilizing the 830-series chassis.

• Heavy Construction: Suitable for any high-pressure open-circuit system requiring variable power management.

Expert Maintenance Tips

• Fluid Cleanliness Protocol: Given the sensitive nature of Load Sensing valves, ensure system oil meets ISO 18/16/13. In forestry environments, always check the reservoir breather for clogs.

• Mandatory Pre-Fill: To prevent immediate catastrophic failure, fill the pump case with filtered hydraulic oil through the case drain port before initial engine startup.

• Thermal Management: Monitor oil temperatures closely. In dense logging environments, radiator blockage can lead to overheating, which is the primary cause of premature bearing and seal failure.