AT45 AT33 AT28 Hydraulic Piston Pump for John Deere 672G Grader

Genlu Hydraulic proudly introduces our AT28, AT33, and AT45 Series Heavy-Duty High-Pressure Open-Circuit Axial Piston Hydraulic Pumps. Specifically engineered to sustain volatile fluid workloads in severe earthmoving and road construction environments, this premium piston pump gallery serves as the critical fluid power generator for John Deere 672G Motor Graders. It supports primary implement operations, frame articulation, and advanced front-wheel auxiliary drive setups (6WD networks). This series delivers a precision-manufactured, field-validated, and exact drop-in replacement for OEM designations including AT457670, 83041431, 83005896, and A174911812.

Motor graders demand highly fluid simultaneous multi-axis control and rapid load-sensing adjustments when performing fine leveling, ditch cutting, or aggressive bank sloping. Genlu’s AT series piston pumps conform tightly to original equipment mechanical and operational matrices. We guarantee 100% Drop-in Interchangeability across standard SAE mounting pilots, splined input drive shafts, high-pressure port connections, and standard Load-Sensing (LS) regulator valve architectures. Prior to leaving our facility, each piston pump undergoes 100% simulated motor grader deep-trenching load adaptation, full-flow transient step-response audits, and low-viscosity high-temperature leakage logging, ensuring reliable pressure retention and structural stability under extreme cyclic duty.

Technical Specifications 

• Product Line: AT28 / AT33 / AT45 Series Heavy-Duty Variable Displacement Load-Sensing Axial Piston Pump

• Target Machine Compatibility: John Deere 672G Motor Grader and corresponding heavy equipment platforms

• Cross-Referenced OEM Part Matrix: AT457670, 83041431, 83005896, A174911812

• Displacement Range: 74 $cc/rev$ to 130 $cc/rev$ (Engineered to match specific grader configurations, such as primary implement circuits or front-wheel auxiliary configurations)

• Continuous Rated Operating Pressure: 28.0 MPa (280 bar / 4060 psi)

• Maximum Intermittent Peak Pressure: 35.0 MPa (350 bar / 5075 psi)

• Permissible Input Shaft Velocity Envelope: 2200 rpm to 2600 rpm

• Control Mechanism Profile: Load Sensing (LS) with integrated Pressure Limiter (DF) override, or electro-proportional displacement trims depending on specific OEM part matching

• Input Drive Shaft Style: Standard heavy-duty SAE involute splined shaft

• Housing Construction Material: High-tensile precision-cast ductile iron anti-fracture casing

Key Technical Advantages:

• Highly Responsive Integrated LS Control Valve Assembly: Features a highly sensitive load-sensing control block that continuously monitors load variations across the grader’s main control valves. When zero implement flow is demanded, the pump deststrokes to a low-pressure standby mode. The moment the moldboard encounters high resistance, the valve adjusts the swashplate angle within milliseconds, delivering excellent multi-function control and optimizing fuel efficiency.

• Bi-Metal Sintered Valve Plate with Hardened 9-Piston Matrix: The inner cylinder block is machined from high-grade alloy steel and layered with a bonded bi-metal copper microstructure. Paired with nine hardened, geometry-optimized pistons, this setup maintains a robust hydrodynamic fluid film between the pistons and slippers even under 35 MPa spikes, reducing internal slippage and friction wear.

• Rigid One-Piece Swashplate for Low Operational Noise: Uses a large-diameter, high-rigidity swashplate supported by heavy-duty cradle bearings. This structural design dampens mechanical vibrations caused by piston reciprocating motion and optimizes internal fluid passaging, substantially dampening fluid hum and airborne noise across all operating speeds.

• Thru-Shaft Capability for Versatile Tandem Mounting: Built with a modular through-shaft configuration that allows tandem coupling of secondary steering, charging, or fan-drive pumps. This setup allows a single engine drive shaft to power independent fluid circuits—such as blade lift, articulation, and cooling fan loops—optimizing engine bay space.

Application Areas:

• Heavy Infrastructure & Road Construction: Primary hydraulic supply for John Deere 672G series motor graders featuring standard tandem or advanced 6WD auxiliary power systems.

• Heavy Duty Earthmoving Implements: Dedicated high-pressure oil supply powering grader moldboard lift, blade tilt, circles-turn gearboxes, and frame articulation cylinders.

Expert Maintenance Tips:

• Pre-Fill the Pump Case Prior to Engine Ignition: The internal rotating kit and sliding components rely entirely on fluid inside the pump housing for cooling and lubrication. After physical installation and before connecting the final lines or starting the engine, fill the pump case with clean hydraulic fluid through the top case drain port until it overflows. Running the pump dry for even three seconds will cause friction scoring on the swashplate and slippers, leading to catastrophic failure.

• Perform a Comprehensive System Flush and Fluid Decontamination: If the original pump failed due to internal breakage or metal shedding, you must thoroughly clean the hydraulic reservoir, flush all control valve lines, and replace all suction and return filters before installing the new unit. Any metal particles left behind will quickly migrate back into the new pump, scoring the precision surfaces and causing premature secondary failure.

• Monitor Case Drain Line Flow and Back-Pressure Closely: Clean flow through the case drain line is vital for cooling internal components and protecting the shaft oil seal. Ensure the drain line routes directly back to the reservoir without restrictions or check valves. If case back-pressure rises above 0.2 MPa, it can blow out the shaft seal or compromise the precision of the variable swashplate mechanism.