Hitachi ZX850-3 ZX850LC-3 ZX870H-3 ZX870R-3 ZX1800K-3 Main Hydraulic Pump

OEM PN: 9249784, 9249785, 4635787, 4635645 | Kawasaki K3V280SH | BELPARTS Large Mining Excavator Spare Parts

• Part Name: Tandem Variable Displacement Axial Piston Main Pump Assembly with Integrated Pilot Pump, Model K3V280SH
• Official OEM Part Numbers:

  Main Pump Assembly: 4635645

  Pump Drive Housing Assembly: 9249784, 9249785

  Fan Auxiliary Pump PN: 4635787 (K5V80S)

  Cross Interchange PN: YA00003063, YA00003076

• Fully Compatible Excavator Models:

  Hitachi ZX850-3, ZX850LC-3

  Hitachi ZX870H-3 (Heavy Duty Version), ZX870R-3 (Reduced Swing)

  Hitachi ZX1800K-3 Super Large Mining Excavator

  Also fits ZX650LC-3, ZX670LCH-3, ZX870LCH-3 series

• Available Conditions: Genuine Original New / Professionally Refurbished / Premium High-Quality Aftermarket New
• Warranty Policy: 12 months for Genuine & Refurbished pumps; 6–12 months for aftermarket assemblies
• Net Weight: Approx. 390 kg
• Stock Status: In stock, shipped out within 3–7 working days after order confirmation

• Exact original Kawasaki K3V280SH design, perfectly matched to Isuzu 6WG1 engine power curve and Hitachi Dash-3 generation hydraulic control system
• Adopts load sensing + constant horsepower dual regulation system, effectively reduces fuel consumption and prevents engine stall under heavy mining, quarrying and bulk earthmoving loads
• Built-in pilot gear pump supplies stable pilot pressure to control boom, arm, bucket, travel and swing hydraulic circuits
• Direct bolt-on replacement, identical mounting flange, port layout, internal oil passages and spline drive shaft; no cutting, machining or modifiion required during field repair installation
• Thick high-strength nodular cast iron housing, hardened cylinder block, wear-resistant piston assembly and valve plate, engineered for long-cycle harsh heavy-duty mining working conditions
• Every unit undergoes full pressure calibration, internal leakage inspection and overall performance bench test before delivery; ISO9001 & CE certified

• Pump Structure: Twin variable axial piston pump assembly
• Single Side Displacement: 280 cm³/rev
• Rated Implement Working Pressure: 31.9 MPa (319 bar)
• Maximum Travel Relief Pressure: 34.3 MPa (343 bar)
• Total Theoretical Output Flow: Approx. 912 L/min @ 1800 RPM
• Pilot Pump Output: 30 L/min, Working Pressure: 3.9 MPa
• Rotation Direction: Counterclockwise (viewed from engine input side)
• Drive Shaft: OEM-matched internal multi-tooth spline dimension

ZX850-3, ZX850LC-3, ZX870H-3, ZX870R-3, ZX1800K-3

Main pump: 4635645, YA00003063, YA00003076

Pump drive assembly: 9249784, 9249785

Fan pump: 4635787 (K5V80S)

ZX650LC-3, ZX670LCH-3, ZX670LCR-3, ZX870LCH-3, Deere 650D, 850DLC

• Over 13 years specialized in hydraulic pumps for 80–180 ton Hitachi large mining excavators
• Three quality grades optional: genuine original Hitachi/Kawasaki factory unit, fully rebuilt refurbished pump with all wear parts replaced, cost-effective high-performance aftermarket replacement
• Rigorous pre-delivery QC procedure: full pressure testing, internal leakage detection and efficiency verifiion before shipment
• Adequate inventory stored in Guangzhou warehouse, flexible sea freight & air freight global shipping solutions
• Professional engineering team provides installation troubleshooting and long-term technical after-sales support
• Economical cost-saving alternative vs expensive Hitachi genuine OEM spare parts

A: Yes, 4635645 main pump matched with 9249784/9249785 drive assembly is universal and fully compatible with standard long carriage, heavy-duty, short tail swing and super large mining ZX1800K-3 configurations.

A:

• 4635645: Complete main hydraulic pump core assembly (K3V280SH)
• 9249784 / 9249785: Front pump drive housing & power transmission assembly connected to engine
• 4635787: Independent cooling fan auxiliary pump (K5V80S) for radiator fan drive

A: Refurbished pump replaces all worn internal consumable parts (piston, valve plate, cylinder block, oil seals), fully bench-calibrated to OEM performance standard with competitive price; Genuine New is original factory brand-new assembly complying with full OEM specifiion.

A: Products are ready in stock, dispatched within 3–7 working days after order confirmation; global sea & air shipping options available.