122-3401 Cat Hydraulic Piston Pump 250Bar

Product Overview

The 122-3401 is a heavy-duty axial variable displacement piston pump assembly engineered specifically for the high-pressure main hydraulic system of Caterpillar (Cat) 446 and 446B backhoe loaders. Fully interchangeable with OEM cross-reference part numbers 9T-5611, 6E-4863, and 237-7627, this pump assembly delivers 100% direct drop-in compatibility with original Caterpillar units. Every pump undergoes 100% full-load simulated factory testing prior to dispatch, guaranteeing superior volumetric efficiency, rapid dynamic response, and long field service life under demanding digging and loading operations.

Technical Specifications

• Primary Model Code: 122-3401 (Cross-reference: 9T-5611, 6E-4863, 237-7627)

• Brand Compatibility: Caterpillar (Cat)

• Equipment Fit: Cat 446, 446B, 420D, 430D, 432D Backhoe Loaders

• Pump Design: Swashplate Axial Variable Displacement Piston Pump

• Displacement: 74 cm³/rev

• Rated Continuous Pressure: 250 bar (3625 psi)

• Peak Operating Pressure: 315 bar (4560 psi)

• Maximum Drive Speed: 2200 rpm

• Control Logic: Load Sensing (LS) & Pressure Compensator (PC)

• Unit Weight: Approx. 42 kg

Key Technical Advantages

• Micro-Finished Bimetallic Metallurgy: Cylinder block and piston shoes feature nitrided high-strength alloy steel paired with sintered bronze valve plates to eliminate internal bypass leakage and maintain volumetric efficiency above 93% under continuous high pressure.

• Precision Load-Sensing Efficiency: Integrated high-response LS control valves dynamically adjust flow output based on real-time implement load demands, drastically reducing engine fuel consumption and thermal buildup.

• 100% Direct Drop-in Fit: Manufactured strictly to original Caterpillar mounting specifications, flange dimensions, shaft splines, and port interfaces, allowing effortless plug-and-play installation without plumbing modifications.

• 100% Simulated Factory Load Testing: Dynamically tested under full continuous pressure and rated RPM on automated test benches to verify zero external leakage and optimal volumetric performance.

Application Areas

• Caterpillar Backhoe Loaders: Primary hydraulic main pump replacement for Cat 446, 446B, 420D, and 430D loader/excavator equipment.

• Mobile Machinery: Universal high-pressure hydraulic power source for wheeled loaders and excavators operating on the Cat hydraulic system platform.

Expert Maintenance Tips

Flush the main hydraulic circuit thoroughly and replace all fluid filters prior to mounting the pump. Maintain oil cleanliness strictly at ISO 18/16/13 (NAS Class 8) or cleaner using ISO VG 46/68 anti-wear hydraulic oil. Always pre-fill the pump housing completely with clean hydraulic fluid through the highest case drain port before initial start-up, cranking the engine briefly without starting to bleed air and prevent dry friction damage to internal bearings and valve surfaces.