日立 EX300-5 液压主泵 – 中国再制造

1. คุณสมบัติเด่นและประโยชน์

• 按照日立OEM标准进行专业再制造 – This main hydraulic pump has been fully disassembled, cleaned, crack‑inspected, and rebuilt in our ISO‑certified facility in China. All worn components – cylinder block, piston assemblies, valve plate, swashplate, bearings, and seals – are replaced with new, high‑quality parts. The result is a pump that delivers performance and reliability comparable to a new unit at a fraction of the cost.

• Original Hitachi tandem axial piston design – The EX300‑5 pump is a variable displacement double (tandem) axial piston pump combining two independent pumping sections in one housing. This design powers travel, swing, boom, arm, and bucket circuits independently, delivering smooth, coordinated multi‑function operation without internal flow loss – exactly as your machine performed when it left the factory.

• Restored 30‑ton class hydraulic power – After remanufacturing, this pump delivers rated working pressure up to 34.3 MPa (≈4,975 psi) and flow matched to the EX300‑5‘s Isuzu B-6SD1T engine (169 kW at 1,900 rpm). With a hydraulic system relief valve pressure of 4,980 psi and operating weight of 31 metric tons, your excavator regains full digging force, fast cycle times, responsive swing, and powerful travel.

• 集成式负载敏感功率控制 – The factory power control (load‑sensing) system is completely rebuilt. It continuously matches pump output to actual working demand, reducing fuel consumption, preventing engine stall under sudden load, and extending the life of the entire hydraulic system. The integral pilot gear pump is also fully remanufactured.

• 高性价比的全新原厂件替代方案 – A new Hitachi main pump for a 30‑ton excavator is a major investment. Our remanufactured pump gives you the same fit, form, and function at a significantly lower price, without sacrificing reliability. Each pump is dyno‑tested on a hydraulic test stand before dispatch.

• 直接螺栓固定替换 – Mounting flanges, drive shaft splines, and hydraulic port configurations are restored to original Hitachi specifications. No modifications, no adapters, no fabrication – your mechanic unbolts the old pump and bolts this one in. Compatible variants include EX300‑5, EX300LC‑5, EX300LCLL‑5, EX300LCLL‑5M, EX330LC‑5, EX350H‑5, EX350K‑5, EX370‑5M, EX370HD‑5 and EX385USR excavators.

• 发货前目视确认 – We send you clear, high‑resolution photographs of the actual remanufactured unit (mounting flange, splines, port threads, castings, overall condition) before packing. You approve shipment – we never ship blind.

• การจัดส่งที่รวดเร็ว – 从我们广州仓库发货，5–8 个工作日。月供应能力 300 台，可接受单件或批量订单。.

2. การสมัคร

The remanufactured Hitachi EX300‑5 main hydraulic pump is ideal for 30‑ton class excavators used in the most demanding job sites:

• 重型建筑与基础设施 – Highway excavation, dam building, bridge footings, and large‑scale earthmoving projects. The restored tandem pump delivers simultaneous boom, arm, and travel power without internal leakage – no power fade, no sluggish response, even on long shifts. Urban development and road construction demand precise hydraulic control, and the load‑sensing system ensures smooth operation whether you‘re trenching near utility lines or working on highway shoulders.

• 采石与骨料生产 – Loading trucks, stockpile management, and material handling in abrasive dust conditions are routine in granite, limestone and basalt operations. New bearings, seals, and wear plates ensure the pump survives where worn units fail. Consistent flow and pressure mean faster cycle times and lower fuel consumption, directly impacting your cost per ton.

• Open‑pit mining support – Site cleanup, overburden removal, road maintenance, drainage works, and equipment pad grading. The pump’s load‑sensing control reduces fuel burn during light‑duty cycles, saving money over thousands of operating hours. In mining environments where dust and vibration are extreme, our remanufactured pump with new seals and bearings provides the reliability you need to keep production moving.

• 拆除与废料处理 – Shock loads and vibration are routine in demolition yards and metal recycling facilities. Our remanufacturing process replaces all wear components, restoring the pump‘s ability to withstand harsh, unpredictable conditions. The integrated power control prevents engine stall when impact loads spike, maintaining consistent attachment power for shears, pulverizers, and hammers.

• 林业与土地清理 – Steep slopes, fallen timber, hidden obstacles, and remote locations demand hydraulic components you can trust. The integral power control prevents engine stall under sudden load spikes, maintaining consistent hydraulic power for saws, grapples, and mulchers. New seals prevent moisture ingress that is common in wet forestry environments.

• Long‑reach & specialized applications – EX300‑5 Long Reach variants are used for river rehabilitation, coastal work, deep trench excavation, and batching plant responsibilities. The high-track models excel in quarry and mining environments with uneven terrain. A reliable main pump is essential for these specialized configurations where hydraulic demand varies constantly.

3. 为何选择 ฮงเท็งต้า ชิ้นส่วน – Quality You Can Trust

At Hongtengda Parts, we have been remanufacturing hydraulic pumps for Hitachi excavators since 2001. We know that a main pump failure on your EX300‑5 stops your job site completely. Our remanufacturing process is not a “clean and reseal” – it is a factory‑grade restoration.

Our 6‑step remanufacturing process:

1. Complete disassembly – The pump is stripped down to individual components: cylinder block, piston assemblies, valve plate, swashplate, bearings, shaft, housing, and control valves.

2. 清洁与裂纹检测 – All parts are thoroughly cleaned and inspected for cracks using dye penetrant testing on critical castings. Irreparable parts are scrapped.

3. 磨损部件更换 – All seals, O‑rings, bearings, and gaskets are replaced with new components. The cylinder block and valve plate are precision‑ground to restore flatness. Piston assemblies are matched as a set and replaced if worn. The swashplate surface is reconditioned.

4. 精密重新组装 – Components are reassembled using OEM torque specifications. Clearance tolerances on the cylinder block / valve plate interface are verified using dial indicators.

5. 液压测试台验证 – The completed pump is mounted to a test stand and run through its full pressure and flow range. We verify operating pressure (up to 34.3 MPa), flow rate, case drain leakage, and load‑sensing control response. A test report is available upon request.

6. 最终质量检查与包装 – The pump is painted, fitted with protective port caps, and packed in a heavy‑duty wooden case for export.

Why our remanufactured pump outperforms cheaper “rebuilt” units:

• New bearings and seals – Many budget rebuilders reuse old bearings to save cost. We do not. All rotating components get new bearings – the single most important factor for pump longevity.

• 精密研磨的磨损表面 – The cylinder block and valve plate are re‑ground to restore flatness. A lapped surface is essential for low internal leakage. Without it, the pump will overheat and lose power within weeks.

• Full test report – Upon request, we provide a test report showing pressure, flow, case drain, and temperature measurements. You see the data before you buy.

您所购得的不是： A used pump with new paint and a set of O‑rings. Our remanufactured pump is restored to meet or exceed OEM performance standards – at a price that makes sense for your EX300‑5.

• 超过 25 年的行业经验 – Founded in 2001, we have remanufactured thousands of pumps for Hitachi, Caterpillar, Komatsu, Kobelco, Volvo, SANY, and many other brands.

• 90% มีสินค้าพร้อมจำหน่าย – EX300‑5 main hydraulic pumps are in stock as remanufactured units, ready for dispatch from our Guangzhou warehouse.

• 24小时发货 – 从我们广州枢纽到您的货代仅需 1 天；国际订单在 24 小时内发货。.

• 发货前目视确认 – We never ship a pump blind. You receive clear photos of the actual unit before packing – you approve, we ship.

• การสนับสนุนทางเทคนิค – Send us your EX300‑5 machine serial number and a photo of the old pump. We confirm compatibility and provide installation guidance within 2 hours.

Send us your Hitachi EX300‑5 machine serial number and a photo of the old pump – we will verify fitment, provide a quote, and document our pre‑shipment inspection within 24 hours.

Critical installation tip for the EX300‑5 remanufactured pump:
– 壳体泄油管路 must be clear and unrestricted. A blocked case drain will blow the shaft seal instantly on first startup.
– Before installing the remanufactured pump, flush the entire hydraulic system and replace all filters. Contaminants from the failed pump will destroy a remanufactured unit just as quickly as a new one.
– 在每个液压连接处使用新的 O 型圈和密封垫圈。重复使用密封件必定导致泄漏。.
– After installation, run the engine at low idle for 2–3 minutes with the pump in neutral, then slowly cycle each function (boom, arm, bucket, swing, travel) to purge air from the system.
– 检查泵与发动机飞轮壳的对中情况——不对中会导致轴承过早失效和轴封泄漏。.

保修说明： 保修期为 3 至 6 个月，具体取决于产品详情。. 我们不为原装二手或再制造零件提供保修服务。. 我们的价值在交付前就已体现：精心的再制造、彻底的测试以及发货前的视觉确认。对于需要保修选项的客户，我们可以提供全新的售后市场单元报价——请咨询我们的销售团队。.

The main hydraulic pump is the heart of your EX300‑5‘s hydraulic system. A reman pump is a transplant from a tired donor with unknown hours. Our remanufactured pump is restored to meet OEM performance standards – not with shortcuts, but with genuine factory‑grade restoration. Send us your EX300‑5 machine serial number – we will confirm compatibility and provide a quote within 24 hours.