Product Introduction:

The 708-1W-00450 is a hydraulic main pump assembly designed for the Komatsu HM400 series articulated dump trucks. It is a critical component that supplies pressurized oil to power the machine's primary hydraulic systems.

1. Installation Location
This pump is installed in the engine compartment of the HM400, driven directly by the engine through a PTO (power take-off) connection. It is typically mounted to the transmission or bell housing, situated to draw oil from the hydraulic tank and supply it to the machine's control valves and actuators.

2. Function
The pump converts mechanical power from the engine into hydraulic flow to drive the steering system and the hoist cylinders that raise and lower the dump body. For the HM400-5 model, the hydraulic system is designed with a hoist relief pressure of 28.4 MPa (290 kg/cm²). This assembly ensures reliable power delivery for both steering control and dump body lifting operations.

3. Maintenance and Service
Common failure symptoms include delayed dump cycles, hydraulic whining under load, steering lag on inclines, or oil leaks at the pump housing. As an internal assembly, it is not user-serviceable. If a major failure is confirmed, replacement of the entire unit with an identical 708-1W-00450 assembly is recommended. Always depressurize the hydraulic system before service.

4. Important Notes
Always verify the part number 708-1W-00450 matches the original component specification, and confirm compatibility with the specific HM400 model variant (e.g., HM400-3, HM400-5). Weighs approximately 588 kg and should be handled with appropriate lifting equipment