421AK ADU049 Eaton Mobile Piston Pump 49cc 280bar

Product Overview

Technical Specifications

• Model: 421AK ADU049 (Full order code example: ADU049R02AE10AA162000000)
• Series Platform: Eaton 420 Series (421AK platform designation)
• Configuration: Axial piston swashplate fixed displacement pump (open circuit)
• Maximum Displacement: 49.2 cm³/rev (3.00 in³/rev)
• Rated Pressure (Continuous): 280 bar (4000 psi)
• Intermittent Pressure: 320 bar (4640 psi)
• Peak Pressure: 350 bar (5075 psi)
• Maximum Flow: 128 L/min (34 gpm) @ 2650 rpm
• Rated Speed: 2650 rpm
• Volumetric Efficiency: ≥ 95% (at rated conditions)
• Rotation: R = Right-hand (clockwise, viewed from shaft end)
• Weight: Approx. 21 kg (46 lbs)
• Control Options: Pressure compensator (C), Remote control (CG), Load sensing (CV), Load sensing + pressure limiting (CVP/CVPC)

• ADU041: 41.0 cm³/rev, 109 L/min @ 2650 rpm, 280 bar, 21 kg
• ADU049: 49.2 cm³/rev, 128 L/min @ 2650 rpm, 280 bar, 21 kg
• ADU062: 62.3 cm³/rev, 158 L/min @ 2600 rpm, 280 bar, 22 kg
• ADU080: Approx. 80 cm³/rev, 280 bar (largest displacement in the 420 Series range)

Key Technical Advantages

Precision Machining & Manufacturing

High Volumetric Efficiency & Power Density

Low Noise & Vibration Design

Long-Life Bearing & Seal System

Flexible Control Options

Application Areas

• Mobile Cranes: Suitable for 20-ton class truck cranes and crawler cranes — hoisting, boom luffing, and slew circuits. The 280 bar continuous rating supports sustained full-load lifting, while the 350 bar peak pressure capability absorbs shock loads from sudden load swings
• Hydraulic Excavators: Serving as auxiliary or pilot pumps for travel motors, slew motors, and work implement circuits
• Wheel Loaders & Scrapers: Providing high-pressure, high-flow hydraulic power for steering systems and work implements
• Agricultural Machinery: Compatible with combine harvesters and large tractors for hydraulic drive and implement control systems
• Mining Equipment: Used in roof bolters, LHD loaders, and other underground mining equipment for traction and work hydraulics
• Forestry Machinery: Adapting to harvesters and forwarders for traction drive and boom hydraulic systems
• Material Handling Equipment: Applied in forklifts and reach stackers for lift and tilt hydraulic circuits

Expert Maintenance Tips

• Installation Alignment: Ensure pump shaft alignment with the drive source (PTO or gearbox) within 0.05mm radial offset and 1° angular deviation. Use a flexible coupling to prevent excessive bearing loads from misalignment. Pre-fill the pump housing with clean hydraulic fluid before startup — dry starting will cause immediate damage.
• Hydraulic Fluid Requirements: Use ISO VG 32-68 anti-wear hydraulic fluid. Fluid cleanliness must meet NAS 1638 Class 7 or ISO 4406 18/16/13 minimum. Maintain fluid temperature between 30-80°C; during cold starts, fluid temperature must not be below 10°C.
• Case Drain Line: The case drain port must be plumbed directly back to the reservoir with a maximum backpressure of 1.0 bar (15 psi). The drain line size must be equal to or larger than the pump case drain port, and no throttling devices or shutoff valves may be installed in the drain line.
• Initial Startup Procedure: After initial installation or extended storage, run the pump at minimum speed (≤ 800 rpm) with no load for 5-10 minutes to pre-lubricate internal components and purge air. Confirm steady oil flow at the case drain before gradually loading to working pressure.
• Preventive Maintenance Schedule: Inspect shaft seal condition and case leakage volume every 2,000 operating hours. When case leakage exceeds 50% of the initial baseline value, schedule a teardown inspection and replacement of worn components. Replace hydraulic fluid and suction strainer element every 5,000 hours or annually, whichever occurs first.