0732004 Original Excavator Nine Hole Plate Retainer Plate for ZX40-5A ZX55

Part number 0732004 is the official part number for Hitachi's original nine hole plate fixing plate. This component is a key fixing and supporting component inside the hydraulic plunger pump or hydraulic motor, responsible for accurately positioning and firmly fixing the nine hole plate (valve plate) in the pump body or motor housing, ensuring the oil circuit seal and precise pressure oil distribution between the plunger cylinder body and the distribution plate, and is the core basic component to ensure the efficient and smooth operation of the hydraulic pump/motor. As an original standard component, it is mainly compatible with multiple Hitachi hydraulic excavators, such as ZX55、ZX70、ZX200、EX220、ZX210、ZX240、ZX250、ZX270、ZX300、EX300、ZX330、ZX450、ZX470、ZX870、EX1100、EX1200 Waiting for the model.
 

The original nine hole plate fixing plate is the core structural component and positioning component inside the hydraulic pump/motor. Its core function is to provide a rigid, flat, and precisely sized installation base for the nine hole plate, and to securely connect it to the pump or motor housing through bolts, bearing complex loads from the nine hole plate and internal oil pressure, ensuring the stability and sealing of the entire distribution pair under high-speed rotation and high-pressure impact. As an original component, it is usually made of high-strength alloy steel (such as carbon steel or alloy structural steel), which undergoes precision machining, heat treatment (such as quenching and tempering), and rust prevention treatment, and has excellent mechanical strength, rigidity, and deformation resistance.

The maintenance core of this nine hole plate fixing plate is to ensure its structural integrity, flatness of the installation surface, and fastening reliability. Regular inspection: Usually conducted during major repairs or disassembly of hydraulic pumps or motors. Before installation, precision measuring tools such as flat plates and feeler gauges should be used to check the flatness of the installation surface. Fault Symptoms: If the hydraulic system experiences weak pump/motor output, abnormally increased noise, high temperature, or severe internal leakage, after ruling out other causes, it is necessary to consider whether the failure of the nine hole plate seal is due to deformation or improper installation of the fixing plate. Daily maintenance should ensure the cleanliness of hydraulic oil to prevent impurities from entering the pump and exacerbating wear.