YD00013056 Excavator Piston Pump for ZX70-5A

The piston pump YD00013056 is one of the original hydraulic main pumps for the Hitachi ZX70-5A (approximately 7-ton class) crawler excavator. The overall working weight of this model is about 6700kg, equipped with a Yangma 4TNV98 engine with a rated power of 42.4kW. The ZX70-5A hydraulic system adopts a "three variable axial piston pump" configuration, and the maximum flow rate of the main pump is 2 × 63 L/min+1 × 52.5 L/min. YD00013056 corresponds to one of the variable axial piston pumps (piston pumps), and its installation interface, shaft extension size, and oil circuit connection are precisely matched with the HIOS hydraulic system of ZX70-5A. This item may also be compatible with similar models such as ZX70-5G, but it is recommended to follow the Hitachi original parts catalog to avoid system mismatch caused by differences in displacement or control methods.

This product is a variable axial piston pump (inclined disc or inclined shaft type), which is the core power component of the ZX70-5A three pump system. Its rated working pressure is 31.4MPa (walking circuit), and the maximum instantaneous pressure can reach over 35MPa; The estimated displacement is in the range of 40-60cc/rev, and it works in conjunction with two other main pumps to provide the required flow for the system. The pump body is made of high-strength cast iron or aluminum alloy, and the surfaces of key friction pairs such as the plunger, slide shoe, and distribution plate are ultra precision ground and plated with hard chromium, with excellent wear resistance and impact resistance. Equipped with intelligent control valves such as pressure cutoff, load sensitivity, and power limitation, it can automatically adjust flow and pressure according to excavation conditions, achieving high efficiency and energy saving. The original pump has undergone strict bench durability and pulse testing to ensure long-term reliable operation within the oil temperature range of -25 ℃ to 90 ℃, with vibration and noise in compliance with Hitachi building standards.

Check the pump body for abnormal vibration, noise, and leakage every 500 hours of daily work. Replace the hydraulic oil and oil suction and return filter elements every 1000 hours or annually (it is recommended to use the original factory specified ISO VG46 anti-wear hydraulic oil). It is strictly prohibited to operate the pump in a state of no oil or excessive oil contamination (NAS level 9 or below). If the system pressure is insufficient or the action is slow, the pilot pressure (ZX70-5A pilot oil circuit pressure is about 3.9MPa), control valve, and relief valve should be checked first. Non professionals should not adjust the internal pressure setting screw of the pump without authorization. The overhaul cycle is usually 8000-10000 working hours, and it needs to be professionally repaired by authorized service providers using original repair kits (including plungers, distribution plates, seals, etc.). Long term shutdown should start the engine every month to allow the hydraulic pump to run for a short period of time to prevent internal corrosion. When disassembling and reassembling, it is necessary to ensure that the alignment error between the pump shaft and the engine shaft is less than 0.1mm to avoid early wear caused by eccentricity.