Product Overview
The 70453-LBG and 78453-LAV belong to the Eaton Vickers 70453/78453 Series medium-duty open-circuit axial piston variable displacement pump family, with a displacement of 45 cc/rev (2.77 in³/rev). These pumps feature a swashplate variable displacement design with pressure compensator or pressure-flow compensator control, delivering continuous working pressure of 210 bar (3045 psi), intermittent peak pressure of 265 bar (3843 psi), and maximum speed of 3000 rpm. The compact aluminum housing weighs only approximately 16 kg, offering an outstanding power-to-weight ratio suited to mobile machinery and agricultural equipment installation.
The 70453-LBG utilizes pressure compensator control. In the model code, 70453 indicates a single pump with auxiliary flange, L indicates left-hand rotation (CCW), and BG is the control configuration code. The 78453-LAV is a variant in the same series with a load-sensing control configuration; its drive shaft and mounting interface are identical to the 70453. Both pumps share identical SAE 2-bolt mounting flanges, drive shafts, and port layouts with the original Eaton Vickers pump, enabling direct bolt-on replacement without piping modification or adapter plates.
Every pump undergoes 100% simulated operating-condition testing before shipment, including rated pressure hold, flow characteristic verification, and control response validation—delivering immediate reliability upon installation.
Technical Specifications
Model Identification:
70453-LBG — 70453 series, with auxiliary flange, left-hand rotation (CCW), pressure compensator control, 45 cc/rev
78453-LAV — 78453 series, load sensing control, 45 cc/rev
70423-LBA — 70423 series, pressure compensator control, 45 cc/rev
Displacement (Full Series):
70422 / 70452: 38 cm³/r (2.32 in³/r)
70423 / 70453: 45 cm³/r (2.77 in³/r)
70122: 19 cm³/r (1.16 in³/r)
70523: 69 cm³/r (4.21 in³/r)
Pressure Ratings:
Continuous working pressure: 210 bar (3045 psi)
Intermittent peak pressure: 265 bar (3843 psi)
Maximum case pressure: 2 bar (25 PSI)
Speed Range:
Maximum speed: 3000 rpm
Minimum speed: 500 rpm
Theoretical Flow and Power:
Maximum flow: 135 L/min at 3000 rpm
Power at standard speed (1500 rpm): 70 kW
Power at maximum speed (3000 rpm): 93 kW
Control Types:
Pressure Compensator (PC) Control — When outlet pressure reaches the compensator setting, the compensator spool shifts against spring force, allowing pump outlet pressure to act on the servo piston. The servo piston pushes the swashplate to reduce the angle, decreasing displacement and flow. When system pressure drops below the setting, spring force returns the compensator spool, and the swashplate returns to full stroke angle
Pressure-Flow Compensator (PFC) Control — Integrates pressure compensation with load-sensing flow regulation
Load Sensing (LS) Control — Automatically adjusts displacement based on load pressure signal; the 78453-LAV uses this configuration
Structural Parameters:
Pump type: Open-circuit swashplate axial piston variable displacement
Mounting flange: SAE 2-bolt
Drive shaft: SAE splined or keyed
Rotation: Left-hand (CCW) or right-hand (CW)
Port position: Side or rear
Housing material: Aluminum alloy
Weight: Approximately 16 kg
Through-drive: Supported (70453/70452 with auxiliary flange)
Hydraulic Fluid and Operating Conditions:
Recommended fluid: Mineral oil-based anti-wear hydraulic oil; optimal viscosity range 10-39 cSt (60-180 SUS)
Cleanliness requirement: ISO 4406 18/13 or higher
Operating temperature range: -29°C to +107°C
Key Technical Advantages
1. Compact Aluminum Housing Delivers Lightweight High Power Density
The 70453/78453 series features a compact aluminum housing design, with single pump weight of only approximately 16 kg. At 45 cc/rev displacement, it achieves 210 bar continuous working pressure and 3000 rpm maximum speed. The outstanding power-to-weight ratio delivers 93 kW at 3000 rpm. The compact axial dimensions fit within the tight installation spaces of mobile and agricultural machinery, while the aluminum housing provides excellent heat dissipation and corrosion resistance.
2. Pressure Compensator Control Ensures Precise Constant Pressure Output
The pressure compensator on the 70453-LBG achieves constant pressure output through a precision servo piston-swashplate control mechanism. When system pressure reaches the compensator setting, the compensator spool shifts, and the servo piston pushes the swashplate to reduce the angle, decreasing displacement. When pressure drops below the setting, spring force returns the swashplate to full stroke. This closed-loop control mechanism maintains system pressure at the set value with fast response and minimal pressure fluctuation.
3. Load Sensing Control Significantly Reduces Energy Consumption
The load sensing control on the 78453-LAV automatically adjusts pump displacement based on actual load pressure at the actuator, delivering only the required flow. When actuators stop, the pump reduces displacement to near zero, maintaining only standby pressure. This control significantly reduces system heat generation and energy loss, with particularly notable energy savings in the intermittent duty cycles of agricultural machinery.
4. Precision-Machined Rotating Group Ensures Long Life and Stable Operation
Piston-cylinder interfaces undergo precision lapping, and the valve plate is optimized to reduce pressure pulsation and flow ripple. The swashplate-type rotating group continuously adjusts output flow by varying the swashplate angle. The case drain port maintains oil level at or above the pump centerline, ensuring the bearings and rotating group receive adequate lubrication. Stable volumetric efficiency is maintained at 210 bar continuous duty with high overall efficiency and long service life.
5. Complete Model Coding Enables Precise Matching and Drop-in Replacement
The 70453/78453 series model code system encompasses product type (single pump/with auxiliary flange), rotation direction, control type, and configuration codes. In 70453-LBG, 70453 indicates a single pump with auxiliary flange, L indicates left-hand rotation, and BG is the control configuration code; in 78453-LAV, 78453 indicates the 78453 series variant, and LAV is the configuration code. The mounting flange, drive shaft spline, and port layout are identical to the original Eaton pump, enabling direct bolt-on replacement.
Application Areas
Large combine harvesters (header lift, reel speed, discharge auger drive)
High-horsepower tractors (rear three-point hitch, PTO controls, auxiliary remote valves)
Large self-propelled crop sprayers (boom folding, chemical pump drive)
Commercial turf equipment (zero-turn mower hydrostatic control circuits)
Compact wheel loaders and skid steer auxiliary hydraulic systems
Industrial power pack auxiliary supply loops
Silage balers and air seeders hydraulic drive systems
Expert Maintenance Tips
1. Pre-Installation Model Verification
Verify the complete model code on the pump nameplate before installation. The 70453-LBG is configured for left-hand rotation (CCW); 70453-RBG is right-hand rotation (CW). Confirm the drive shaft spline specification matches the equipment. Ensure drive shaft-to-coupling concentricity within 0.05 mm. Install the pump such that the case drain maintains oil level at or above the unit centerline; oil level must be at or above the centerline before starting.
2. Hydraulic Fluid Cleanliness Requirements
Use anti-wear hydraulic oil conforming to SAE J1165. Cleanliness level must be maintained at ISO 4406 18/13 or higher, which allows a maximum of 2,500 particles per mL of 5 μm and 80 particles per mL larger than 15 μm. Optimal viscosity range: 10-39 cSt (60-180 SUS). Viscosity at standard temperature should not fall below 6 cSt; at minimum expected starting temperature, unloaded system viscosity should not exceed 432 cSt.
3. Case Drain Line Installation
Provide a properly sized case drain line to limit case pressure to a maximum of 2 bar (25 PSI). The drain line end should always remain submerged below the reservoir oil level. When combining two or more pumps, the combined torque required must not exceed the torque rating of the input drive shaft of the front piston pump.
4. First Start-Up Procedure
Before first start, confirm the suction line is properly sealed, the reservoir is at the correct level, and oil level is at or above the pump centerline. Run at 500-800 rpm unloaded for 5-10 minutes to purge air. Confirm no suction line leakage and steady oil flow from the case drain line before gradually increasing speed and loading to rated conditions. Recommended filtration is recommended.
5. Routine Maintenance
Replace hydraulic oil filters every 2,000 operating hours or annually. Periodically inspect the pump exterior for leaks and check the drive shaft seal for aging or cracks. If flow decline or pressure instability is observed, prioritize inspection of the valve plate and piston-cylinder wear. Recommended overhaul interval: no more than 8,000 operating hours or 5 years. Always refer to Eaton official repair manual No. 6-631 during installation.
