4411440 Original Excavator Parts Arm Oil Pipe for Hitachi EX1900

Part number 4411440 is a specialized part number for Hitachi's original excavator arm oil pipe. This oil pipe is a key high-pressure pipeline in the hydraulic system of excavators that connects the main control valve group with the boom cylinder. It is responsible for transmitting high-pressure hydraulic oil to accurately control the lifting action of the boom. As an original standard component, it is mainly suitable for multiple series of hydraulic excavators from Hitachi, such as the ZX series (such as ZX200, ZX220, ZX250, ZX300, etc.) and the EX series (such as EX200, EX300, etc.). This part may correspond to a universal high-pressure hydraulic hose assembly in the aftermarket, but to ensure that its pressure resistance level, diameter size, joint thread specification, bending radius, and length fully match the original hydraulic circuit and spatial layout of the vehicle, and to avoid installation interference, pressure loss, or abnormal wear caused by dimensional deviations, it is necessary to verify the complete model of the specific excavator and the accurate installation position of the oil pipe (such as left/right side, inlet/return oil circuit).

This original arm oil pipe belongs to a multi-layer steel wire reinforced high-pressure hydraulic hose assembly. Its core function is to withstand the high-pressure pulses generated by the hydraulic system during excavator operation (the working pressure can usually reach 35MPa or higher), and safely and efficiently deliver hydraulic oil from the main control valve to the boom cylinder. It is the "blood vessel" that achieves strong and smooth movement of the boom. As an original component, it is usually made of inner oil resistant synthetic rubber, multi-layer high-strength steel wire weaving or winding reinforcement layer, and outer wear-resistant and weather resistant synthetic rubber or polyurethane sheath, which has excellent high pressure resistance, pulse fatigue resistance, oil resistance (compatible with various hydraulic oils), high and low temperature resistance (-40 ° C to 120 ° C), as well as resistance to external impact, wear and ozone aging performance.

The maintenance core of this arm oil pipe lies in regular inspections, preventive replacements, and standardized installation operations. Before replacement, be sure to completely release the hydraulic system pressure (operate the pilot handle and release the fuel tank cap). Use a specialized wrench during disassembly to avoid damaging the joint threads. When installing new oil pipes, it is necessary to ensure that their direction is smooth, without distortion, and there is sufficient expansion and contraction allowance to avoid interference with moving parts. Tighten the joints in a staggered manner according to the torque values specified in the maintenance manual. After installation, the system must be purged and the equipment must be slowly operated on the boom for pressure testing. All joints must be checked for leaks before normal operation can be resumed.