Hitachi ZAX70-6 Main Hydraulic Pump – China Remanufactured (AP2D36 / 4437197)

Description

Detail Information

Note: The application information provided is for reference only. Please confirm the part number and compare it with the old component before purchasing. If you have any questions, please feel free to contact us.
It is worth choosing a product that features stable performance, high reliability, easy installation, and quick response.

1. Key Features & Benefits

• Precision-remanufactured AP2D36 tandem piston pump – This main hydraulic pump (OEM 4437197, model AP2D36) is a variable displacement tandem axial piston pump. It has been completely disassembled, cleaned, crack-inspected, and rebuilt in our ISO-certified facility. All wear components – cylinder block, piston assemblies, valve plate, swashplate, bearings, and seals – are replaced with new, high-quality parts. The result is performance and reliability comparable to a new unit at a fraction of the cost.

• Original Rexroth/Uchida AP2D36 design for 7‑ton class excavators – The AP2D36 is a proven hydraulic platform used across multiple Hitachi models. This pump delivers a rated working pressure of up to 26.5 MPa (265 bar) and operates at speeds up to 2,600 rpm. It powers the boom, arm, bucket, swing, and travel circuits with smooth, responsive hydraulic flow.

• Integrated load‑sensing (LS) and pressure compensation (PC) control – The factory control system is fully rebuilt and calibrated. It continuously matches pump output to actual joystick demand, reducing fuel consumption, preventing engine stall under sudden load, and extending the life of the entire hydraulic system. The result is precise, predictable machine response – critical when working around utilities or in tight spaces.

• Dual‑flow logic for simultaneous functions – The pump is engineered to handle multiple hydraulic demands at once – for example, travelling while operating the boom – without stalling the engine. This keeps cycle times fast and machine performance consistent.

• New bearings and precision‑ground wear surfaces – All bearings are replaced – never reused. The cylinder block and valve plate are re‑ground to restore flatness, ensuring minimal internal leakage, cooler oil, and better efficiency. Superior metallurgy in these components reduces internal friction and keeps oil temperatures stable during long shifts.

• Direct bolt‑on replacement – Mounting flange, drive shaft spline, and hydraulic port configurations are restored to original Hitachi/Rexroth specifications. No modifications, no adapters – your mechanic unbolts the old pump and bolts this one in.

• Hydraulic test stand validated – Each remanufactured pump is run on a test stand to verify rated pressure, flow, case drain leakage, and control response. A test report is available upon request.

• Pre‑shipment visual verification – We send you clear, high‑resolution photographs of the actual pump (mounting flange, splines, port threads, castings) before packing. You approve – we ship. Never blind.

• Fast delivery – 5–8 working days from our Guangzhou warehouse. Monthly capacity 300 units.

2. Applications

The remanufactured Hitachi AP2D36 main pump (4437197) is ideal for 7‑ton class excavators used in a variety of job sites:

• Urban construction & utilities – Sidewalk repairs, water/gas line trenching, fibre‑optic cable installation. The pump’s load‑sensing control provides precise, “fine‑touch” flow for delicate digging near existing utilities – eliminating the “dead zones” common with aftermarket pumps.

• Residential landscaping & pool excavation – Pool digs, retaining walls, grading, and drainage work. The pump’s smooth response and quiet operation are essential for noise‑sensitive neighbourhoods.

• Agriculture & land management – Drainage ditch cleaning, irrigation trenching, pond maintenance, and fence post holes. The pump’s high pressure (265 bar) provides the attachment power needed for augers, trenchers, and rippers.

• Mining support & quarry maintenance – Site cleanup, equipment pad grading, and light aggregate handling. Abrasive dust and vibration demand robust seals and bearings – our reman process delivers new components to withstand these harsh conditions.

• Equipment rental fleet – Mini excavators are the most frequently rented machines. A remanufactured pump offers predictable service life (3,000–5,000 hours) at a cost that makes proactive replacement financially sensible – avoiding costly mid‑rental failures.

• Forestry & vegetation clearance – Steep slopes, fallen timber, hidden obstacles. The integral power control prevents engine stall under sudden load spikes, maintaining consistent power for saws, grapples, and mulchers.

3. Why Choose Hongtengda Parts – Remanufacturing That Actually Works

Many hydraulic shops offer “rebuilt” pumps. They disassemble, replace O‑rings, add new paint, and call it done. The cylinder block remains scored. The valve plate remains warped. The bearings remain fatigue‑cracked. Within 500–1,000 hours, internal leakage returns, oil temperature climbs, and you lose power again.

Our remanufacturing is different. We replace what is worn, not just what leaks.

Our 6‑step process:

1. Complete disassembly – Pump stripped to every component: cylinder block, pistons, valve plate, swashplate, bearings, shaft, housing, control valves.

2. Cleaning & crack inspection – All parts cleaned, critical castings dye‑penetrant inspected. Irreparable parts scrapped.

3. Wear component replacement – All seals, O‑rings, bearings, gaskets replaced. Cylinder block and valve plate re‑ground to original flatness. Piston assemblies replaced as matched set if worn. Swashplate reconditioned.

4. Precision reassembly – Assembled using OEM torque specs. Clearance tolerances verified.

5. Hydraulic test stand validation – Tested for rated pressure (265 bar), flow, case drain leakage, and load‑sensing response. Test report available.

6. Final quality check & packaging – Painted, port caps fitted, packed in heavy‑duty wooden case.

What you are buying: A pump with new bearings, new seals, ground wear surfaces – restored to OEM performance. Not a band‑aid.

What you are not buying: A used pump with fresh paint and a set of O‑rings.

• 25+ years of industry experience – Founded in 2001, remanufactured thousands of pumps for Hitachi, Caterpillar, Komatsu, Kobelco, Volvo, SANY, and others.

• 90% stock availability – AP2D36 pumps (4437197) in stock as remanufactured units in Guangzhou warehouse.

• 24‑hour shipment – From Guangzhou hub to forwarder in 1 day; international orders within 24 hours.

• Pre‑shipment visual verification – Never blind. You receive photos, you approve, we ship.

• Technical support – Send machine serial number and old pump photo. Compatibility confirmed within 2 hours.

Send us your Hitachi ZAX70-6 (or ZX70) machine serial number and a photo of the old pump – we will confirm fitment and provide a quote within 24 hours.