Product Overview
The AT223519, AT180826, AT191574, AT197383, AT227996, and AT180926 all belong to the Oilgear AT Series swashplate-type axial piston variable displacement pump family, serving as OEM-replacement main hydraulic pumps for John Deere construction machinery. Featuring a swashplate variable displacement design with pressure compensator and load sensing control, the AT Series delivers continuous working pressures up to 350 bar (5075 psi), maximum pressures reaching 420 bar (6090 psi), and 92% hydraulic efficiency—making it ideal for the hydraulic systems of backhoe loaders, wheel loaders, and motor graders.
The mounting flange, drive shaft spline, and port layout of the AT Series maintain 1:1 dimensional compatibility with original John Deere pumps. The AT223519 fits John Deere 544H wheel loaders and TC54H tractors; the AT191574 and AT197383 fit John Deere 410E and 410G backhoe loaders; the AT227996 fits John Deere 744J wheel loaders. The pump body features a high-strength cast iron housing with precision valve block and integrated mounting flanges, ensuring reliable operation under high-pressure continuous duty.
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:
AT223519 — Fits John Deere 544H wheel loader, TC54H tractor, 6068 engine
AT197383 — Fits John Deere 410E / 410G backhoe loaders (sub for AT191574)
AT191574 — Fits John Deere 410E / 410G backhoe loaders, weight 114 lbs
AT180926 — Fits John Deere 410E / 410G backhoe loaders (sub for AT428960)
AT227996 — Fits John Deere 744J wheel loader
AT180826 — AT Series same-platform model
Displacement Range:
Pressure Ratings:
Rated continuous working pressure: 300-350 bar (4350-5075 psi)
Maximum pressure: 420 bar (6090 psi)
Peak pressure: 483 bar (+15% pressure tier available)
Speed Range:
Control Types:
Swashplate Variable Displacement Control — Displacement infinitely adjustable between zero and maximum
Pressure Compensator (PC) Control — Automatically reduces displacement to maintain constant pressure when system pressure reaches the set value
Load Sensing (LS) Control — Automatically adjusts displacement based on load pressure signal, delivering only the flow required by actuators
Optional controls: electro-proportional control, torque control
Structural Parameters:
Pump type: Swashplate axial piston variable displacement
Housing material: High-strength cast iron with corrosion-resistant black coating
Mounting flange: OEM standard integrated mounting flange
Drive shaft: Splined shaft (specification model-dependent)
Port connections: SAE standard flange ports
Built-in components: Pressure regulator, torque limiter
Recommended fluid: ISO VG32 / VG46 / VG68 anti-wear hydraulic oil
Key Technical Advantages
1. Complete OEM Drop-in Interchangeability
The AT Series pumps maintain 1:1 dimensional matching with original John Deere pumps in mounting flange, drive shaft spline, port position, and overall dimensions—direct replacement without any mechanical modification. The AT223519 directly replaces the original pump in John Deere 544H loaders, the AT191574 and AT197383 are interchange models for 410E/410G backhoe loader main pumps, and the AT227996 is the interchange model for the 744J loader main pump. This design eliminates the high cost and downtime associated with waiting for original factory parts.
2. 92% High Hydraulic Efficiency Reduces Operating Costs
The AT Series features optimized piston mechanisms and precision valve plate design, achieving 92% hydraulic efficiency—reducing energy loss by up to 20% compared to conventional piston pumps. In construction machinery such as backhoe loaders and wheel loaders requiring extended continuous operation, this efficiency gain directly translates to reduced fuel consumption and lower operating costs.
3. 420 bar High-Pressure Capability for Heavy-Duty Applications
The AT Series is rated at 300-350 bar continuous working pressure with maximum pressure up to 420 bar (6090 psi) and peak pressure reaching 483 bar (+15% pressure tier). The high-strength cast iron housing and precision-machined internal friction pairs maintain stable volumetric efficiency under high-pressure continuous duty, with low internal leakage ensuring reliable operation in harsh job site environments.
4. Modular Design Simplifies Maintenance
The AT Series features a modular structural design with built-in pressure regulator and torque limiter, enabling quick disassembly and replacement. Precision-matched friction pairs are manufactured from high wear-resistant materials, effectively extending service life and reducing equipment maintenance downtime. Optional pressure compensation, load sensing, or electro-proportional control adapts to different operating condition requirements.
5. Wide Speed Range for Diverse Drive Conditions
The AT Series operates at speeds from 1500 to 3000 rpm, flexibly adapting to equipment engine output speeds and control configurations. The swashplate variable displacement structure enables stepless continuous displacement adjustment, responding to dynamic load changes in the hydraulic system and ensuring precise flow output under varying operating conditions.
Application Areas
John Deere 410E / 410G backhoe loader main hydraulic pump (AT191574 / AT197383 / AT180926)
John Deere 544H wheel loader main hydraulic pump (AT223519)
John Deere TC54H tractor hydraulic system (AT223519)
John Deere 744J wheel loader hydraulic system (AT227996)
John Deere motor grader hydraulic systems (AT302661 and derivative models)
Construction machinery hydraulic system retrofit and overhaul replacement
Heavy-duty construction equipment hydraulic power units
Agricultural machinery hydraulic drive systems
Expert Maintenance Tips
1. Pre-Installation Model Verification
Verify the complete model code on the pump nameplate before installation. AT Series mounting flanges and drive shaft specifications vary by model—while both the AT223519 and AT227996 belong to the AT Series, they may fit different equipment and have different mounting dimensions. Ensure drive shaft-to-coupling concentricity within 0.05 mm to prevent premature seal and bearing failure from radial loads. Install the pump such that the case drain maintains oil level at or above the unit centerline.
2. Hydraulic Fluid Cleanliness Requirements
Use ISO VG32 / VG46 anti-wear hydraulic oil with optimal operating viscosity range of 10-39 cSt. Fluid cleanliness should be ISO 4406 18/13 or higher, allowing a maximum of 2,500 particles per mL of 5 μm and 80 particles per mL larger than 15 μm. Suction filter rating should be no coarser than 10 μm. Operating oil temperature range: -20°C to +90°C. Flush the system thoroughly before first operation to eliminate residual metallic particles.
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 to prevent air ingestion. When replacing an AT Series pump, it is recommended to simultaneously replace seals in the suction and pressure lines to ensure system sealing integrity.
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 low speed 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. The pressure compensator setting can be adjusted via the adjustment screw on the control valve.
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 spline and shaft seal for wear. If flow decline, pressure instability, or insufficient output torque is observed, prioritize inspection of the valve plate and piston-cylinder wear. AT Series pumps are fully rebuild-able, with rebuild kits available separately. Recommended overhaul interval: no more than 8,000 operating hours or 5 years.
