Komatsu PC78US-6 ミニエキスカベータのためのMain 708-3T-00252 油圧ポンプ

1. Product Identification & Compatibility
This pump assembly is a direct "bolt-on" replacement for the following Komatsu factory part numbers:

Primary OEM Part Number: 708-3T-00252

Interchangeable Numbers: 708-3T-00114, 708-3T-00215, 708-3T-00216

Machine Fitment: Komatsu PC78US-6, PC78UU-6, and PC78MR-6 series excavators.

2. Technical Specifications
Type: Tandem Variable Displacement Axial Piston Pump.

Control System: Integrated Load-Sensing (LS) and Pressure Compensator (PC) valves.

Rated Pressure: Nominal operating pressure of 28.5 MPa (285 bar).

Construction: Heavy-duty cast iron housing with precision-lapped valve plates and hardened cylinder blocks.

Design Benefit: Compact tandem design allows for high power density, fitting perfectly within the tight engine compartment of the "Ultra Short" (US) chassis.

3. Why Choose Our Professional Grade Pumps?
Precision Calibration: Every pump is pre-set to Komatsu factory pressure and flow specifications. This ensures the machine tracks straight and the boom/arm speeds match original performance.

100% Bench Tested: Each unit undergoes a rigorous dynamometer test. We verify volumetric efficiency, case drain leakage, and response times of the LS valves under full load.

Material Quality: We use premium internal components (piston sets, friction plates, and seals) that meet or exceed OEM hardness and thermal expansion standards.

Express Logistics: Units are secured in shock-proof export wooden crates. Express delivery via DHL, FedEx, or UPS typically arrives in 3 to 7 business days.

4. Critical Installation Requirements
To protect your investment and ensure a valid warranty, the following steps are mandatory:

Case Priming: Before starting the engine, you must fill the pump housing with clean hydraulic oil via the highest case drain port. Running the pump "dry" for even a few seconds will cause catastrophic failure of the piston shoes.

System Decontamination: If the previous pump suffered a mechanical failure (metal in the system), the hydraulic tank must be cleaned, and the oil cooler and main control valve must be flushed.

Filter Replacement: Always install a new high-efficiency suction strainer and return filter (ISO VG46 oil is recommended).

Air Bleeding: After installation, run the engine at low idle and cycle all hydraulic cylinders to their stroke ends several times to purge air from the system.

5. Ordering & Support
To ensure 100% accuracy for your machine, please have the following ready:

Machine Serial Number (Found on the chassis plate).

Photos of your existing pump’s data plate if possible.