100-3259 Caterpillar Axial Piston Pump 416B 428B 250bar

Product Overview

Technical Specifications

• Model: 100-3259 (Cross-reference: 1003259 / 0R-9645)
• Configuration: Variable-displacement axial piston swashplate pump (open circuit)
• Hydraulic System Type: Load-sensing, closed center (LSPC)
• Rated Working Pressure: 250 bar (3625 psi)
• System Relief Valve Setting: 250 bar / 3626 psi (428B); 207 bar / 3000 psi (416B)
• Rated Speed: 2200 rpm
• Rated Flow (@ 2200 rpm): Approx. 160 L/min (42.3 gpm)
• Maximum Displacement: Approx. 65 cm³/rev (derived from flow and speed data)
• Control Method: Pressure compensation + Load sensing (LSPC)
• Weight: Approx. 27 kg (60 lbs) — P/N 100-3259; Approx. 38 kg (83.78 lbs) — P/N 0R-9645 (remanufactured assembly)
• Rotation: Clockwise viewed from shaft end (standard configuration)
• Compatible Machines: Caterpillar 416B / 426B / 428B / 436B / 438B / 428

• 416B: System pressure 3000 psi (207 bar), total flow 41 gpm (155 L/min)
• 428B: System pressure 3626 psi (250 bar), pump capacity 42.3 gpm (160 L/min) @ 2200 rpm
• 438B: System pressure 250 bar, load-sensing closed-center system

Key Technical Advantages

Precision Machining & Manufacturing

Load-Sensing Energy Efficiency

Low Noise & Vibration Design

Long-Life Bearing & Seal System

Application Areas

• Caterpillar 416B Backhoe Loader: Serves as the main hydraulic pump, providing high-pressure hydraulic power for loader bucket lift/tilt, backhoe boom/stick/bucket cylinders, and swing motor — system pressure 207 bar, flow 155 L/min
• Caterpillar 426B/428B Backhoe Loader: Powers the complete hydraulic system including loader work tools, backhoe excavation implements, fully hydrostatic steering system, and braking circuits — system pressure 250 bar, flow 160 L/min
• Caterpillar 436B/438B Backhoe Loader: Meets the hydraulic system demands of larger-tonnage machines, providing stable high-pressure, high-flow hydraulic power for heavy-duty excavation and loading operations
• Municipal Construction: Applied in the above machine models for urban utility line installation, road maintenance, trenching, and other municipal construction scenarios
• Agricultural & Ranch Operations: Compatible with backhoe loaders for ranch fencing, irrigation ditch digging, material handling, and general farm construction tasks
• Rental Fleet Refurbishment: Serves as a core replacement component for hydraulic system refurbishment of aging equipment, restoring machines to factory-original performance levels

Expert Maintenance Tips

• Installation Alignment: Ensure pump shaft alignment with the drive source (engine gearbox or PTO output shaft) within 0.05mm radial offset and 1° angular deviation. Use a flexible coupling or direct spline connection to prevent excessive bearing loads from misalignment. Pre-fill the pump housing with clean hydraulic fluid before startup — dry starting will cause irreversible damage to the piston-cylinder and valve plate within seconds.
• Hydraulic Fluid Requirements: Use Caterpillar DEO™ or equivalent ISO VG 32-68 anti-wear hydraulic fluid. Fluid cleanliness must meet ISO 4406 18/16/13 minimum. Maintain fluid temperature between 30-80°C; during cold starts, fluid temperature must not be below 10°C — perform low-speed warm-up if necessary. Hydraulic tank capacity is approximately 79-95 liters (depending on machine model); always maintain fluid level within the dipstick range.
• Case Drain Line: The case drain port must be plumbed directly back to the reservoir with a maximum backpressure of 1.0 bar (15 psi). The drain line size must be equal to or larger than the pump case drain port, and no throttling devices or shutoff valves may be installed in the drain line. Regularly monitor case drain volume — a significant increase indicates accelerated wear of the piston-cylinder assembly or valve plate, necessitating teardown inspection.
• Load-Sensing System Commissioning: After pump replacement, the load-sensing system must be pressure-matched. Verify the load-sensing signal line (LS Line) is correctly connected and leak-free, and that the pressure compensator setting matches factory specifications (250 bar for the 428B). After system startup, observe the pump standby pressure reading in no-load condition — the normal value should be approximately 20-30 bar below the system relief valve setting.
• Preventive Maintenance Schedule: Inspect shaft seal condition and case leakage volume every 2,000 operating hours. Replace hydraulic fluid and suction strainer element every 5,000 hours or annually, whichever occurs first. Sample hydraulic fluid every 1,000 hours to test cleanliness and moisture content, replacing fluid that fails to meet specifications. Total hydraulic system capacity is approximately 95 liters (428B); during fluid changes, always replace filters and clean the tank simultaneously.