Product Overview
The A4VG40EP4DM1/32R-NSC02F005DP is a Bosch Rexroth A4VG Series swashplate-type axial piston variable displacement pump with a displacement of 40 cm³/rev, belonging to the Series 32 closed-circuit high-pressure pump family. Featuring EP4 electric proportional control (with DM1 control module variant), it operates at a nominal pressure of 400 bar and can withstand peak pressures up to 450 bar, purpose-built for hydrostatic closed-circuit drive systems in construction machinery, agricultural equipment, and municipal vehicles. The series covers displacement sizes including A4VG28, A4VG40, A4VG56, A4VG71, A4VG90, A4VG125, A4VG180, and A4VG250.
The A4VG series pump features flow proportional to drive speed and displacement, infinitely variable via swashplate actuation, with smooth flow direction change as the swashplate crosses neutral — enabling forward-reverse control without directional valves. An integrated auxiliary pump serves as boost and pilot oil supply, with high-pressure relief valves that also function as boost valves, and a standard integrated pressure cut-off valve. Manufactured to original Bosch Rexroth specifications with guaranteed drop-in interchangeability, this pump directly replaces the OEM A4VG40 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, EP4 control response verification, and leakage inspection.
Technical Specifications
A4VG40EP4DM1/32R-NSC02F005DP Primary Parameters:
Model: A4VG40EP4DM1/32R-NSC02F005DP
Series: Rexroth A4VG Series 32
Type: Swashplate axial piston variable displacement pump (closed circuit)
Displacement: 40 cm³/rev
Nominal Pressure: 400 bar
Maximum Pressure: 450 bar
Maximum Speed (nmax): 4,000 rpm
Maximum Flow (at nnom): 160 L/min
Maximum Power (nnom, Vg max, Δp=400 bar): 107 kW
Maximum Torque (Vg max, Δp=400 bar): 255 N·m
Auxiliary Pump Displacement (at p=20 bar): 8.6 cm³/rev
Control Type: EP4 electric proportional control (with DM1 control module)
Rotation: Clockwise (R = right-hand, viewed from shaft end)
Mounting Flange: SAE standard flange
Weight: Approx. 31 kg (without through drive)
Auxiliary Pump: Integrated
Pressure Cut-off: Standard integrated
Hydraulic Fluid: Mineral-based hydraulic oil (ISO VG 32–68)
Filtration: ISO 4406 cleanliness level 20/18/15 or better
A4VG Series 32 (Size 28–125) Common Specifications:
Displacement Range: 28, 40, 56, 71, 90, 125 cm³/rev
Nominal Pressure: 400 bar (full series)
Maximum Pressure: 450 bar (full series)
Maximum Speed Range: 2,850–4,250 rpm (depending on size)
Maximum Flow Range: 119–275 L/min
Mounting: SAE standard or metric flange options
Through Drive: Mounting of additional pump of same nominal size
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 A4VG40 utilizes a swashplate-type axial piston variable pump design. 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. The displacement mechanism responds rapidly to load changes, ensuring precise and smooth actuator motion.
2. EP4 Electric Proportional Control — Precise Remote Control and System Integration
EP4 control receives electrical signals through proportional solenoids, combined with the DM1 control module for precise proportional displacement regulation. The control method supports remote electronic operation and seamlessly integrates with machine electronic control systems, 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, effectively protecting hydraulic components from overpressure damage.
3. Integrated Auxiliary Pump with High-Pressure Relief Valve Protection
An integrated auxiliary pump serves as both boost and pilot oil pump, maintaining positive pressure in the closed circuit, preventing cavitation, and compensating for system leakage. The auxiliary pump shares the drive shaft with the main pump, requiring no additional mounting space or drive interface. Two high-pressure relief valves protect the high and low pressure sides respectively, and also function as boost valves — automatically supplying charge oil when circuit pressure drops below boost pressure. Maximum boost pressure is limited by the built-in relief valve for safe system operation.
4. High Power Density with Compact Lightweight Design
The A4VG40 delivers 107 kW maximum power at 40 cm³/rev displacement and 400 bar nominal pressure while weighing only approximately 31 kg, achieving an excellent power-to-weight ratio. The pump housing is cast from high-strength iron, and the rotating group is based on the proven A4VG series design. The compact axial dimensions with standard SAE mounting flange suit space-constrained mobile machinery installations.
5. 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.
Application Areas
The A4VG40EP4DM1/32R-NSC02F005DP is widely used in the following equipment:
Vibratory roller propel drive systems
Mini excavator main hydraulic pump systems
Skid steer loader hydrostatic transmissions
Telescopic handler hydraulic transmissions
Agricultural machinery (tractor hydraulic drive systems)
Municipal sweepers and snow removal equipment
Concrete pump truck hydraulic drives
Material handling equipment propel circuits
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.
EP4 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 auxiliary pump start-up.
