3108109 Excavator Hydraulic Pump Retainer Plate for ZX120-3

The Hitachi original excavator hydraulic pump fixing plate (part number: 3108109, often referred to as the "nine hole plate" or "nine hole plate" in the field of accessory circulation) is a key installation substrate for connecting the hydraulic pump assembly to the engine or frame. This part is mainly suitable for Hitachi ZX120 excavators, and its design may also be compatible with similar models such as ZX130-5A (please note that ZX130-5A may use different part numbers, such as 3065989). As the original part number, 3108109 is a universal identification code that needs to be recognized during procurement.

This fixed plate is the core load-bearing and positioning component of the hydraulic pump assembly. Its core function is to provide a sturdy and flat installation reference for hydraulic pumps (usually variable displacement piston pumps), and to use high-strength bolts to rigidly connect the pump body to the engine flywheel housing or frame through nine precision machined holes on it, ensuring precise alignment between the two. As an original component, it is usually cast from high-strength cast iron or alloy steel and precision machined, with excellent deformation resistance and fatigue strength, capable of withstanding the huge torque, vibration, and impact loads generated during the operation of hydraulic pumps.

The maintenance core of the hydraulic pump fixing plate itself lies in regularly checking the fastening status and structural integrity. Due to its long-term exposure to alternating stress and vibration, a torque wrench should be used every 500 working hours or during regular maintenance to check and re tighten all installation bolts according to standard torque values (specific values can be found in the equipment maintenance manual) to prevent misalignment caused by looseness. When disassembling the hydraulic pump for major repairs, it is necessary to carefully clean the installation surface of the fixing plate to ensure that there is no oil stains, rust or burrs, and use a ruler to check its flatness. If obvious deformation or cracks are found, they must be replaced immediately.