Product Overview
The 421AK00018C is a core configuration of the Eaton Vickers 420/X20 series open-circuit axial piston pump, built on the ADU062 platform with a displacement of 62.3 cc/rev (3.80 in³/rev). This pump employs a variable swashplate design with a cast-iron, one-piece housing architecture that contains 25% fewer components than conventional piston pumps, directly eliminating potential leak paths and simplifying maintenance. Related models in the 421AK family include 421AK00311A and 421AK01088B.
The 420 series is manufactured within Eaton’s global production system. The field-proven rotating group enables continuous operation at 280 bar (4060 psi) with intermittent capability to 320 bar (4600 psi). The pump’s standard pressure-and-flow (load sense) compensator maintains a low standby pressure of approximately 10 bar (150 psi) with exceptional stability, minimizing heat generation and wasted energy.
Every 421AK00018C, 421AK00311A, and 421AK01088B unit we supply is manufactured to original Eaton drawing tolerances. Mounting flange geometry (SAE B 2-bolt, SAE J744-101-2), input shaft spline (13-tooth, 16/32), port layout, and compensator control logic are dimensionally identical to the genuine article — delivering true drop-in interchangeability. Each pump undergoes 100% simulated load testing across the full pressure range from rated to peak before shipment.
Technical Specifications
421AK00018C Specific (ADU062 Platform):
Model: 421AK00018C
Platform Model: ADU062 (62.3 cc/rev configuration)
Full Model Code: ADU062R05AA10AA431400000100100CD00C
Pump Type: Open-circuit axial piston, variable displacement, swashplate design
Displacement: 62.3 cc/rev (3.80 in³/rev)
Continuous Pressure: 280 bar (4060 psi)
Intermittent Pressure: 320 bar (4600 psi)
Peak Pressure: 350 bar (5000 psi)
Rated Speed (at 1 bar abs inlet): 2600 rpm
Max Speed (at 2 bar abs inlet): 2800 rpm
Control Type: Pressure & Flow (Load Sense) Compensator
Mounting Flange: SAE B 2-bolt (SAE J744-101-2)
Input Shaft: 13-tooth, 16/32 spline
Housing Material: Cast iron
Weight (single seal, reference): approximately 23.8 kg
421AK01088B Specific (ADU062 Platform):
Model: 421AK01088B
Platform Model: ADU062 (62.3 cc/rev configuration)
Full Model Code: ADU062R05AB10A2824000A2AB100CD0B
Rotation: Clockwise (right-hand)
Mounting Flange: SAE B 2-bolt
Displacement: 62.3 cc/rev
Continuous Pressure: 280 bar
Other parameters consistent with ADU062 platform
421AK00311A Parameters (420 Series General Platform):
Model: 421AK00311A
Series: Eaton Vickers 421AK Series
Pump Type: Open-circuit axial piston pump
Displacement Range (series coverage): 41–80 cc/rev
Continuous Pressure: 280 bar (4060 psi)
Intermittent Pressure: 320 bar (4600 psi)
Specific displacement configuration per factory test report
420 Series Cross-Platform Reference:
Displacement: ADU041=41.0 cc/rev, ADU049=49.2 cc/rev, ADU062=62.3 cc/rev, ADU080=80.0 cc/rev
Continuous Pressure: ADU041/049/062=280 bar, ADU080=210 bar
Intermittent Pressure: ADU041/049/062=320 bar, ADU080=250 bar
Rated Speed (1 bar abs inlet): ADU041=2650 rpm, ADU049=2650 rpm, ADU062=2600 rpm, ADU080=2500 rpm
Single Seal Weight: ADU041/049=22.9 kg, ADU062=23.8 kg, ADU080=24.2 kg
Specifications compiled from Eaton 420 Mobile Piston Pump Technical Manual E-PUPI-TM002-E5 (September 2017) and published engineering data for equivalent configurations.
Key Technical Advantages
One-Piece Housing & Lightweight Design. The 420 series employs a single-piece housing that reduces the number of sealing interfaces from 3–4 (typical of multi-piece designs) to just one, directly eliminating potential leak points. The pump contains 25% fewer components than traditional piston pumps, and maintenance requires no multi-layer housing disassembly — significantly reducing downtime. The cast-iron housing maintains structural rigidity while keeping the 62 cc pump at 23.8 kg, suitable for compact engine bay installations.
Load Sense Control & Low Standby Pressure. The 421AK00018C comes standard with a pressure-and-flow (load sense) compensator that adjusts displacement in real time to match load demand. Standby pressure is maintained at approximately 10 bar (150 psi) with exceptional stability, virtually eliminating throttling losses during standby and reducing oil temperature rise and fuel consumption. This control characteristic is particularly critical for excavators and loaders with frequent combined operations.
High Power Density Rotary Group & Wide Speed Range. The field-proven axial piston rotary group delivers a maximum speed of 2800 rpm (at 2 bar abs inlet) in the 62 cc displacement class, with maximum theoretical power output of 60.8 kW. This power density allows OEMs to downsize engine compartments under Tier 4 emission standards while maintaining job-site productivity.
Multi-Control Options & System Integration Flexibility. The 420 series supports seven control configurations: pressure compensation, load sense, torque control, remote pressure control (RPC), electronic displacement control (EDC), EH inverse proportional pressure control (IPPC), and electronic de-stroke (cold start) valve. The same pump platform can be adapted to different host machine requirements by swapping the control module alone — no changes to mounting flange or port layout required. This modular architecture dramatically simplifies OEM inventory management and aftermarket service.
Application Areas
The 421AK00018C (62 cc) plus 421AK00311A and 421AK01088B are specified for the following mobile and industrial hydraulic systems:
Construction: Mid-size excavators (boom/arm/swing circuits), backhoe loaders, skid-steer loader main hydraulic circuits
Agriculture: Large tractor auxiliary hydraulics, combine harvester hydraulic drives
Municipal Vehicles: Refuse compactor hydraulic power units, snow removal equipment
Material Handling: Mid-size telehandlers, truck-mounted crane hydraulic systems
Industrial: Hydraulic power unit main pumps, press high-pressure circuits
Expert Maintenance Tips
Pre-Installation Checks. Verify that the mounting flange is SAE B 2-bolt (SAE J744-101-2) and the input shaft spline is 13-tooth, 16/32. The suction line diameter must support self-priming at the 2600 rpm rated speed (ADU062 rated flow approximately 158 L/min). Use a suction filter rated at 10 μm or finer. Ensure the mounting flange face and drive-end mating surface are free of oil, debris, and burrs, and that the O-ring seal is intact.
First Start-Up. Fill the pump housing with clean hydraulic oil (ISO VG32 or VG46, cleanliness ISO 18/16/13) before initial start. Jog the starter 2–3 times to confirm rotation direction — the 421AK00018C and related models are standard right-hand (clockwise, viewed from shaft end). Run unloaded for 5 minutes, then ramp to rated pressure gradually. The pressure-and-flow compensator is factory-set. If adjustment is required, turn the adjustment screw clockwise in increments not exceeding 1/4 turn, then tighten the locknut.
Routine Maintenance. Inspect case drain flow every 500 hours — a significant increase typically indicates piston/bore wear or valve plate scoring. Replace suction and return filter elements every 2,000 hours. Maintain oil cleanliness at ISO 18/16/13 or better and keep oil temperature below 80°C. The 420 series housing design supports in-situ control module replacement without disconnecting the pump from the drive end — a feature that significantly reduces field service time.
