705-58-45030 Hydraulic Pump Ass’y for Komatsu WA800-3E0 WA900-3 Wheel Loader

For Komatsu WA900 and WA900L wheel loaders: a hydraulic pump ass’y, part number 705-58-45040 that delivers the flow and pressure that every hydraulic function depends on.

Category: Hydraulic Pump Assembly

Description
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705-58-45040 Hydraulic Pump Ass’y is a replacement hydraulic pump ass’y for Komatsu wheel loaders, including WA900, WA900L. The main hydraulic pump converts engine power into pressurized oil flow. Supplied by LIONKITS.

705-58-45040 Hydraulic Pump Ass’y Specifications

Product Type: Hydraulic Pump Ass’y
Part Number: 705-58-45040, 7055845040
Compatible Brand: Komatsu
Machine Type: Wheel Loader
Country of Origin: China

Komatsu Models Compatible with the 705-58-45040 Hydraulic Pump Ass’y

Komatsu Wheel Loader
Fitment Details: WA900 S/N 50001-UP WHEEL LOADERS WA900L S/N 52001-UP WHEEL LOADERS

Your model is not listed? Contact LIONKITS via live chat or email with your machine model and nameplate photo, and we will confirm compatibility.

What Does a Hydraulic Pump Do?

The main hydraulic pump converts engine power into pressurized oil flow. That oil moves the boom, arm, bucket, swing and travel functions, so every machine movement depends on it. Because it takes the most punishment, it is usually the first major hydraulic component to wear out.

Signs the Part Needs Replacing

Slow or weak movement on all functions: when everything is slow at once, not just one circuit, the pump is the most likely source.
Whining, knocking or grinding noise: internal wear or cavitation, especially on start-up or when the oil is cold.
Hydraulic oil running hot: internal bypass leakage turns pressure into heat.
Metal particles in the filter or case drain: a failing pump sheds metal and pushes out more case drain flow.
Erratic or spongy movement, foamy oil: air entering the suction line, or aeration, upsets pump flow.

These symptoms overlap with clogged filters, low oil, air in the suction line and worn valves, so check the filters and oil level before replacing the part.

How to Order and Install the 705-58-45040 Hydraulic Pump Ass’y

Confirm your machine model, the part number and the pump model on your existing pump before ordering.
Send a photo of the old pump or the nameplate if you are not sure; LIONKITS will confirm fitment for you.
Change the hydraulic oil and the return filters before fitting the new pump; a new pump installed in contaminated oil will fail early.
If the old pump failed internally and shed metal, flush the tank, hoses and oil cooler and inspect the control valve and motors for contamination.
Fill the pump case with clean hydraulic oil and prime the pump as the service manual specifies before the first start.
Check the suction line, strainer and fittings for air leaks, and tighten bolts to the specified torque.
Run the machine at low speed first, then check pressure, noise and leaks.

Frequently Asked Questions

What is the 705-58-45040 Hydraulic Pump Ass’y?

The 705-58-45040 Hydraulic Pump Ass’y is a replacement hydraulic pump ass’y for Komatsu wheel loaders under part numbers 705-58-45040, 7055845040.

Which Komatsu models does the 705-58-45040 Hydraulic Pump Ass’y fit?

It is listed for WA900, WA900L and other models in the compatibility list above. If you are unsure, send your machine nameplate to LIONKITS for confirmation.

How do I know my hydraulic pump is failing?

Typical signs are slow or weak movement on all functions, whining or knocking noise, hot hydraulic oil, metal particles in the filter or case drain and erratic or spongy movement.