Mastering Komatsu Hydraulic Pump Flow Adjustment for Smooth Operation

When it comes to Japanese imported machines, the Komatsu excavator stands out for its exceptional performance and 

durability, winning the hearts of machine enthusiasts in the Chinese market. However, regardless of the series, after thousands 

of hours of operation in various construction environments, Komatsu excavators encounter the challenge of adjusting the 

hydraulic pump. Today, we delve into the meticulous process of adjusting thehydraulic pump  flow on a Komatsu excavator.

Principle of Operation: The hydraulic pump plays a crucial role in providing pressure oil to operate hydraulic components like 

motors and cylinders. In the Komatsu excavator, the main pump consists of pump 1 and pump 2, with the output shaft connected 

to the cylinder body of each pump through the plunger. As the output shaft rotates with the cylinder body, the plunger absorbs 

and discharges the hydraulic oil. To regulate the main pump flow, the cylinder's inclination angle is adjusted, altering the piston 

stroke based on the angle. This adjustment is achieved through the up and down movement of the servo piston, controlling the 

increase or decrease in main pump flow.

Adjustment Method of Komatsu Hydraulic Pump:

Maximum Flow Adjustment:

Loosen the regulator lock nut 1 and adjust screw 2. Clockwise adjustment increases the flow, while counterclockwise reduces it. 

Ensure the adjustment screw 2 does not rotate more than two circles.

Minimum Flow Adjustment:

Loosen regulator lock nut 3 and adjust screw 4. Clockwise reduces flow, counterclockwise increases it. Rotate screw 4 no more 

than two turns during adjustment.

Hydraulic Pump Torque Adjustment:

Loosen regulator lock nut 7 and adjust screw 8. Clockwise adjustment increases torque, counterclockwise reduces it. Additionally, 

loosen locking nut 9 and adjust screw 10 for torque adjustments. Rotate the adjustment screw no more than one lap, monitor 

engine power changes, and tighten locking nut 9 after proper adjustment.

While the article presents a comprehensive guide to adjusting the hydraulic pump on a Komatsu excavator, mastering this process 

is not easy. Without maintenance experience or skills, operators must handle the adjustments with care to ensure optimal performance 

and longevity of the hydraulic system.