Product Overview
The A4VG180EP4D1/32R-NZD02F741SH is a Bosch Rexroth A4VG Series swashplate-type axial piston variable displacement pump with a displacement of 180 cm³/rev, belonging to the Series 32 closed-circuit high-pressure pump family (OEM Material # R902125622 / R992001959). The associated model A4VG180EP2D1/32R-NTD02F691LH-S (OEM Material # R902061144) shares the same Series 32 platform with EP2D1 control configuration and a different shaft/port specification combination.
The A4VG series pump is a swashplate-type axial piston variable pump, optimized for closed-circuit hydrostatic transmission. Flow is proportional to drive speed and displacement, and is infinitely variable. As the swashplate swings out, flow increases from zero to maximum; when the swashplate crosses the neutral position, the flow direction changes smoothly without the need for directional valves. The series features an integrated charge pump serving as both boost and pilot oil pump, with high-pressure relief valves that also function as feed valves, and standard integrated pressure cut-off.
Manufactured to original Bosch Rexroth specifications with guaranteed drop-in interchangeability, this pump directly replaces the OEM A4VG180 series pump without modification to mounting interfaces or hydraulic plumbing. Every unit undergoes 100% simulated working-condition dyno testing prior to shipment, including rated pressure cycling, EP control response verification, and leakage inspection.
Technical Specifications
A4VG180EP4D1/32R-NZD02F741SH Primary Parameters:
Model: A4VG180EP4D1/32R-NZD02F741SH
OEM Material #: R902125622 / R992001959
Series: Rexroth A4VG Series 32
Type: Swashplate axial piston variable displacement pump (closed circuit)
Displacement: 180 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed (nmax): 2,850 rpm
Maximum Flow (at nmax): Approx. 356 L/min
Maximum Input Torque (Δp=400 bar): Approx. 1,145 N·m
Control Type: EP electric proportional control (proportional solenoid)
Rotation: Clockwise (R = right-hand, viewed from shaft end)
Mounting Flange: SAE standard flange (metric version)
Weight: Approx. 101 kg
Charge Pump: Integrated
Pressure Cut-off: Standard integrated
Case Drain Port: Standard
Hydraulic Fluid: Mineral-based hydraulic oil (ISO VG 32–68)
Filtration: ISO 4406 cleanliness level 20/18/15 or better
A4VG180EP2D1/32R-NTD02F691LH-S Primary Parameters:
Model: A4VG180EP2D1/32R-NTD02F691LH-S
OEM Material #: R902061144
Series: Rexroth A4VG Series 32
Type: Swashplate axial piston variable displacement pump (closed circuit)
Displacement: 180 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed (nmax): 2,850 rpm
Maximum Flow (at nmax): Approx. 356 L/min
Control Type: EP electric proportional control (EP2D1 configuration)
Weight: Approx. 101 kg
A4VG Series 32 Common Specifications (Size 180):
Displacement Range: 28, 40, 56, 71, 90, 125, 180, 250 cm³/rev
Nominal Pressure: 400 bar (full series)
Maximum Pressure: 450 bar (full series)
Maximum Speed (Size 180): 2,850 rpm
Charge Pump Displacement (Size 180): Approx. 39.8 cm³/rev
Mounting: SAE standard or metric flange options
Through Drive: Mounting of additional pump of same nominal size at rear
Control Options: NV, DG, EZ, HD, HW, DA, EP, EP3, EP4, etc.
Key Technical Advantages
1. Swashplate Closed-Circuit Design with Smooth Zero-Position Reversal
The A4VG180 utilizes a swashplate-type axial piston variable pump design optimized for closed-circuit hydrostatic transmission. The swashplate swings steplessly from neutral in both directions, with flow increasing smoothly from zero to maximum. When the swashplate crosses the neutral position, flow direction changes smoothly without the need for directional valves. This characteristic is particularly suited for bidirectional speed control in propel drive systems, simplifying hydraulic circuit design and reducing system costs.
2. EP Electric Proportional Control — Precise Remote Control and System Integration
EP control receives electrical signals through proportional solenoids, enabling precise proportional displacement regulation. Both EP4D1 and EP2D1 are electric proportional control configurations, distinguished by different suffix codes for specific control module specifications. The control method supports remote electronic operation and seamlessly integrates with machine electronic control systems (such as propel controllers), enabling fine control, closed-loop speed control, and engine-pump power matching. The standard integrated pressure cut-off automatically reduces pump displacement to zero when system pressure reaches the set value.
3. Integrated Charge Pump with High-Pressure Relief Valve Protection
An integrated charge pump serves as both boost and pilot oil pump, maintaining positive pressure in the closed circuit, preventing cavitation, and compensating for system leakage. Two high-pressure relief valves protect the high and low pressure sides respectively, and also function as feed valves — automatically supplying charge oil when circuit pressure drops below charge pressure. Charge pressure is limited by the built-in charge pressure relief valve for safe system operation.
4. Through Drive with Multi-Pump Tandem Capability
The A4VG series offers a through drive configuration, allowing an auxiliary pump of the same nominal size to be mounted directly on the rear of the pump, forming a compact tandem assembly without separate support brackets or additional drive interfaces. This modular design significantly reduces axial installation length, reducing system complexity and installation costs, particularly for mobile machinery requiring multiple pump operation.
5. High-Strength Cast Iron Housing and Long-Life Bearing System
The pump housing is cast from high-strength iron with optimized structural design, balancing 400 bar pressure capability with compact construction. The drive shaft is supported by large-diameter bearings capable of withstanding both the axial forces from swashplate displacement and radial loads from the drive end. Bearing preload is precisely calculated to maintain stable running clearance across the full speed range, extending service life.
Application Areas
The A4VG180EP4D1/32R-NZD02F741SH and A4VG180EP2D1/32R-NTD02F691LH-S are widely used in the following equipment:
Vibratory roller propel drive systems
Motor grader propel hydraulic circuits
Wheel loader hydrostatic transmissions
Concrete pump truck hydraulic drives
Mining LHD propel circuits
Agricultural machinery (tractor hydraulic drive systems)
Heavy forklifts and material handling equipment
Municipal specialty vehicle hydraulic transmissions
Expert Maintenance Tips
Pre-Installation Checks: Verify that the pump shaft spline matches the drive end configuration before installation. Apply a light coating of grease to the spline surface. Ensure full contact between the mounting flange and the mounting pad. Tighten fixing bolts to the specified torque values. Never force the pump into position by tightening the fixing bolts, as this may cause abnormal bearing preload or housing deformation. Confirm that the rotation direction (R = right-hand, viewed from shaft end) matches the drive end.
Oil Cleanliness Control: A4VG series pumps are sensitive to fluid contamination. System oil cleanliness should be maintained at ISO 4406 level 20/18/15 or better. Under 400 bar high-pressure operating conditions, a cleanliness level of 19/17/14 is recommended. Suction filters should be rated at 10 μm or finer; charge pressure filters at 10 μm or finer are recommended. Check suction line sealing before first start-up to prevent air ingress.
EP Control Module Maintenance: Periodically inspect the electric proportional control module wiring and connectors for tightness. Control signal lines should be routed away from high-voltage ignition lines and other electromagnetic interference sources. If sluggish displacement response or system oscillation is observed, first inspect the control module electrical connections, proportional solenoid operation, and pressure control valve settings.
Case Drain Management: The case drain line must remain unrestricted; case pressure must not exceed the rated value. Route the drain line directly to the reservoir below the oil level to avoid backpressure affecting pump displacement control. Periodically inspect the drain line for loosening or wear caused by vibration.
Start-Up and Break-In: During initial start-up, operate at low speed and low pressure for 10–15 minutes to purge air from the system and check all connections for leakage. Fill the pump case with clean hydraulic oil through the case drain port before starting to prevent dry-start damage to the rotary group. Ensure the suction line is filled with hydraulic fluid before charge pump start-up. With a total pump weight of approximately 101 kg, use appropriate lifting equipment during handling and installation to avoid component damage from improper operation.
