| # |
Part No. |
Description |
Qty |
|
4635645 |
PUMP; PISTON |
1 |
| 01 |
4661507 |
. PUMP; REGULATOR |
1 |
| 011 |
0718001 |
. PISTON ASS'Y |
1 |
| 011A |
---- |
.. PISTON |
9 |
| 011B |
---- |
.. SHOE |
9 |
| 014 |
0703002 |
. CYL. ASS'Y |
1 |
| 014A |
---- |
.. BLOCK; CYL. |
1 |
| 014B |
---- |
.. PLATE; VALVE |
1 |
| 030 |
0716801 |
. PLATE ASS'Y |
1 |
| 030A |
---- |
.. PLATE |
1 |
| 030B |
---- |
.. BUSHING |
1 |
| 111 |
0682301 |
. SHAFT; DRIVE |
1 |
| 123 |
0682302 |
. BRG.; ROL. |
1 |
| 124 |
0682303 |
. BRG.; NEEDLE |
1 |
| 127 |
0339809 |
. SPACER |
1 |
| 130 |
0682304 |
. BOOSTER |
1 |
| 153 |
0718002 |
. RETAINER |
1 |
| 156 |
0828401 |
. BUSHING |
1 |
| 157 |
0682307 |
. SPRING |
9 |
| 211 |
0682309 |
. PLATE |
1 |
| 251 |
0981101 |
. SUPPORT |
1 |
| 261 |
0682311 |
. COVER |
1 |
| 263 |
0981102 |
. COVER |
1 |
| 271 |
0981103 |
. CASING |
1 |
| 312 |
0682314 |
. COVER |
1 |
| 325 |
0682315 |
. COVER |
1 |
| 401 |
0682316 |
. BOLT; SOCKET |
4 |
| 403 |
0111530 |
. BOLT; SOCKET |
6 |
| 406 |
M340820 |
. BOLT; SOCKET |
4 |
| 408 |
0102411 |
. BOLT; SOCKET |
3 |
| 466 |
. PLUG |
2 |
| 468 |
0175233 |
. PLUG |
3 |
| 490 |
0263019 |
. PLUG |
27 |
| 491 |
0451027 |
. SCREW |
2 |
| 492 |
0451028 |
. PLUG |
2 |
| 530 |
0800706 |
. PIN ASS'Y |
1 |
| 530A |
---- |
.. PIN |
1 |
| 530B |
---- |
.. PIN |
1 |
| 532 |
0800707 |
. PISTON; SERVO |
1 |
| 534 |
0682319 |
. STOPPER |
1 |
| 535 |
. STOPPER |
1 |
| 702 |
4292386 |
. O-RING |
1 |
| 706 |
. O-RING |
1 |
| 710 |
0682321 |
. O-RING |
1 |
| 717 |
. O-RING |
2 |
| 719 |
0682323 |
. O-RING |
1 |
| 724 |
. O-RING |
10 |
| 725 |
4297379 |
. O-RING |
4 |
| . O-RING |
0443408 |
. O-RING |
3 |
| 732 |
0682324 |
. O-RING |
1 |
| . SEAL; OIL |
0682325 |
. SEAL; OIL |
1 |
| 789 |
0682326 |
. RING; BACK-UP |
1 |
| . RING; BACK-UP |
0682327 |
. RING; BACK-UP |
1 |
| 808 |
0451038 |
. NUT |
2 |
| . RING; RETAINING |
960323 |
. RING; RETAINING |
1 |
| 885 |
0313404 |
. PIN |
1 |
| . PIN; SPRING |
4144353 |
. PIN; SPRING |
2 |
| 901 |
0134458 |
. BOLT; EYE |
2 |
| . SCREW |
0339847 |
. SCREW |
1 |
| 954 |
0682328 |
. SCREW; SET |
1 |
| . PLATE |
---- |
. PLATE |
1 |
| 983 |
0625509 |
. PIN |
2 |
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
1. Basic Information
- 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
2. Key Features
- 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 modification 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
3. Technical Specifications (K3V280SH)
- 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
4. Compatibility & Cross Reference List
Direct Fit Machine Models
ZX850-3, ZX850LC-3, ZX870H-3, ZX870R-3, ZX1800K-3
Full Interchangeable Part Numbers
Main pump: 4635645, YA00003063, YA00003076
Pump drive assembly: 9249784, 9249785
Fan pump: 4635787 (K5V80S)
Extended Compatible Models
ZX650LC-3, ZX670LCH-3, ZX670LCR-3, ZX870LCH-3, Deere 650D, 850DLC
5. BELPARTS Competitive Advantages
- 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 verification 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
6. FAQ
Q1: Does this pump fit all five listed ZX850/ZX870/ZX1800-3 models?
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.
Q2: What is the function difference between 9249784, 4635645 and 4635787?
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
Q3: What is the difference between Refurbished and Genuine New pump?
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 specification.
Q4: What is your delivery lead time?
A: Products are ready in stock, dispatched within 3–7 working days after order confirmation; global sea & air shipping options available.