Description
HPV091 4254445 Hydraulic Pump Assembly Overview
The HPV091 4254445 Hydraulic Pump assembly (OEM Part Numbers: 4254445, 4281787, 4189398, HPV091) manufactured by Tatan is a heavy-duty Hitachi/Kawasaki series axial piston double pump belonging to our Hydraulic Pump Assembly classification. Engineered specifically for Hitachi EX120-2, EX120-3, and EX120-5 12-to-13 ton excavators, replacing your worn main pump with a Tatan complete HPV091 4254445 Hydraulic Pump unit restores original 31.4 MPa working pressure and rapid digging cycle times instantly.
Built strictly to original Hitachi OEM specifications, this hydraulic main pump assembly features 1:1 mounting flange dimensions and a 13-teeth spline shaft that couples directly to Isuzu 4BD1 engine flywheels without hose or regulator modifications.
Key Attributes & Parameters for HPV091 4254445 Hydraulic Pump
| Product Category | Hydraulic Pump Assembly | Warranty | 1 Year / 12 Months |
| Specific Pump Model | Hitachi / Kawasaki HPV091 Pump | Brand Name | Tatan |
| Compatible Equipment | Hitachi EX120-2 | EX120-3 Excavator | OEM Part Number | 4254445 / HPV091 |
| Matched Engine Series | Isuzu 4BD1 / 4BD1T Diesel Engine | Place of Origin | Guangdong, China |
| Max Relief Pressure | 31.4 MPa (314 bar / 4550 PSI) | Rated Flow Output | 2 x 91 L/min + Gear Pilot Pump |
| Drive Shaft Spec | 13-Teeth Spline Shaft (13T / CW) | Control Mechanism | Hydraulic Open Center & Regulator |
| Machinery Test Report | Provided (100% Bench Tested) | Video Outgoing-Inspection | Provided Before Shipping |
| Quality Status | 100% Brand New Complete Unit | Packaging | Export Wooden Box Packaging |
Supported Machinery Brands & Hydraulic Pump Coverage
In addition to Hitachi, Tatan manufactures replacement main hydraulic pumps and components for major excavator brands:
Application Scenarios & Buyer Value
When rebuilding or replacing aging hydraulic systems with our HPV091 4254445 Hydraulic Pump, workshops and equipment owners eliminate repetitive downtime:
| Application Scenario | Value Delivered to Buyer |
|---|---|
| Hitachi EX120-2 Hydraulic Restoration | 1:1 direct bolt-on installation eliminates hydraulic lag and restores original digging speed and gradeability. |
| Hydraulic Repair Workshops | Replaces complex internal cylinder barrel rebuilding; reduces overhaul hours and eliminates aftermarket warranty risks. |
| Utility & Drainage Contractors | Heavy-duty bimetallic components withstand continuous 31.4 MPa rock-breaking and trenching operations. |
| Export Parts Stockists | High-demand replacement pump ready for immediate resale to overseas contractors and plant hire fleets. |
HPV091 4254445 Hydraulic Pump OEM Diagnostic Guide
Use this OEM manual hydraulic diagnostic guide to troubleshoot operational symptoms on your Hitachi EX120-2 excavator:
| Hydraulic Symptom | Technical Cause Analysis | Tatan Factory-Grade Solution |
|---|---|---|
| 1. Slow boom/arm operation & weak travel under high oil temp | Bimetallic valve plate or cylinder block surface scoring causing high-pressure internal oil bypass (>31.4 MPa drop). | Install Tatan HPV091 4254445 Hydraulic Pump complete assembly; flush tank lines and replace 10μm oil return filter. |
| 2. Engine stalling / Lugging down when pulling hydraulic pilot levers | Regulator control spool sticking or torque spring fatigue, overloading the Isuzu 4BD1 engine under relief. | Disassemble and clean regulator; lap spool clearance to 0.005mm tolerance or install a new complete pump assembly. |
| 3. Loud cavitation noise & oil foaming in hydraulic reservoir | Air ingress through suction flange O-rings or cracked suction rubber hose causing vacuum cavitation. | Reseal suction intake with high-temp HNBR O-rings; check hydraulic oil level and bleed air from pump casing. |
| 4. Front shaft oil seal blowout into engine flywheel housing | Casing drain line blockage or internal bypass wear causing drain pressure to exceed 0.2 MPa. | Clear case drain return lines, replace front shaft seal with high-pressure NOK seal, and test casing relief pressure. |
Transport Packaging & Fast Global Shipping
To ensure 100% damage-free international transport, every Tatan HPV091 4254445 hydraulic main pump is preserved with anti-corrosion oil, sealed in heavy poly film, and strapped inside an export-grade wooden crate.
✈️ Express Air Courier
Partnered with DHL, FedEx, UPS, and TNT for 3-7 day express door-to-door delivery worldwide.
🚢 Sea Cargo Freight
LCL and FCL ocean container shipping for heavy hydraulic pump assemblies and bulk orders.
📦 Export Wooden Cases
Fumigated solid wooden boxes with custom high-density foam inserts to prevent shipping shock.
Quality Control & International Certificates
Tatan hydraulic components are manufactured under ISO 9001 certified quality control systems and strictly comply with CE safety standards.
HPV091 4254445 Hydraulic Pump FAQ & Related Categories
* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote.
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