B0600-21031 172961-73102 Main Hydraulic Pump for Yanmar VIO45-5 VIO55-5B VIO55-6A VIO55-6B Mini Excavator (Point-by-Point Layout)

1. OEM Part Number & Machine Compatibility

• Yanmar OEM part numbers: B0600-21031, 172961-73102
• Original pump configuration: Variable displacement piston pump assembly with integrated pilot gear pump
• Fully compatible mini excavator models: Yanmar VIO45-5, VIO55-5B, VIO55-6A, VIO55-6B
• Unified mounting flange, input shaft spline and hydraulic port layout allows direct replacement across all listed machine versions

2. Core Technical Specifications

• Structure type: Combined unit of variable axial piston main pump and built-in pilot charge gear pump
• Internal displacement and flow parameters follow factory hydraulic design matched for VIO45 and VIO55 series platform
• Rated continuous working pressure meets original system standard, with preset maximum relief pressure for overload protection
• Operating speed range precisely calibrated to match original engine output specification for these excavator models
• Mounting hole positions, shaft size and port direction strictly comply with OEM dimensional drawings
• Pump housing constructed from ductile iron; internal pistons, valve plates and friction components use quenched alloy steel for improved wear resistance and longer service lifespan

3. Internal Structure & Functional Introduction

• Main piston pump delivers high-pressure hydraulic oil to actuate boom, arm, bucket, travel and swing working motions
• Integrated pilot gear pump supplies steady pressure oil to feed pilot control circuits and replenish system hydraulic oil volume
• Internal power adjustment regulator modulates pump flow output automatically in response to load variations, preventing engine stall during heavy digging operations
• Compact integrated design reduces occupied space inside the narrow hydraulic compartment of small mini excavators

4. Product Advantages

• Exact 1:1 OEM outer casting dimensions, enabling plug-and-play installation without adjustments to hydraulic piping or machine mounting structure
• Every finished pump undergoes full hydraulic bench inspection covering pressure stability, flow uniformity and internal leakage testing prior to delivery
• Full range of maintenance spare parts kept in stock, including overhaul seal kits, piston assemblies, swash plates and valve plates for separate component replacement during repair work
• Two interchangeable part numbers suit four machine models, lowering inventory management workload for spare part dealers and repair service shops

5. Packaging & Global Delivery Details

• Input shaft and all hydraulic ports coated with anti-rust grease and sealed with protective dust plugs
• Entire pump wrapped with moisture-proof plastic film and secured inside export-grade solid wooden crate to prevent collision and moisture damage during long-distance sea or air transit
• In-stock products can be arranged for shipment within 3 to 5 working days after order confirmation
• Multiple global shipping choices available: international air express, sea LCL/FCL bulk shipment and overland truck transportation for Southeast Asian customers

6. FAQ

• Q: Are B0600-21031 and 172961-73102 interchangeable with each other?
  
  
  A: Yes, these two part numbers refer to the same hydraulic pump assembly with identical internal structure and installation size, suitable for cross replacement on all applicable Yanmar models.
• Q: Can this pump install directly on all four listed VIO series excavators?
  
  
  A: Yes, consistent mounting dimensions and matched hydraulic calibration support direct bolt-on fitting for VIO45-5, VIO55-5B, VIO55-6A and VIO55-6B with no extra modification required.
• Q: Are individual repair components offered for this hydraulic pump?
  
  
  A: Corresponding complete overhaul seal kits, piston shoe assemblies, valve plates, swash plates and standalone pilot gear pump spare parts are all available for partial overhaul and component replacement work.