YB00003191 Original Excavator Hydraulic Pump Head Cover for Hitachi ZX330-5A ZX350-5A

The Hitachi original hydraulic pump cover (part number: YB00003191) is a key sealing component of Hitachi excavator hydraulic pumps. According to industry general information, this part is mainly suitable for medium and large excavators in Hitachi ZX series (such as ZX200, ZX220, ZX250, etc.) and EX series (such as EX200, EX300, etc.), which may include models such as ZX200-5G, ZX220-5G, ZX250-5G, EX200-5, EX300-5, etc. Its common or associated part numbers may include 9101521, 9145787, etc

The top cover of the hydraulic pump is the "pressure portal" of the hydraulic pump. Its core function is to seal the pump body, withstand the high pressure inside the hydraulic system (usually up to 35MPa or more), and ensure the static sealing of the connection parts between the pump body and the transmission shaft, inlet and outlet, etc., to prevent high-pressure hydraulic oil leakage. At the same time, it provides stable support and positioning for internal rotating components such as gears and plungers. As an original component, it is usually made of high-strength aluminum alloy or cast iron precision casting, which has excellent compressive, deformation and corrosion resistance properties. The sealing surface is precision machined to ensure the flatness and roughness requirements for fitting with the pump body, and integrates multiple sealing grooves for installing sealing components such as O-rings and metal gaskets, forming a reliable composite sealing system.

Daily inspection: It is recommended to visually inspect the joint surface between the top cover and the pump body, the bolt connections, and the oil pipe interface for any oil leakage every 250 working hours. Regular maintenance: Combined with the major maintenance of the equipment every 2000 working hours, check and re tighten all fixing bolts according to the specified torque (usually 18-25N · m), clean the oil and debris on the top cover surface and heat dissipation ribs, and ensure good heat dissipation. Seal replacement: When a leak is found or during disassembly and maintenance, all sealing rings (O-rings, gaskets) must be inspected and replaced. Before installing a new seal, the sealing groove must be cleaned and an appropriate amount of lubricating grease applied.