31LB-00400 Hyundai HL770 Double Vane Pump 210bar

Product Overview

The 31LB-00400 (31LB00400) is the main double vane pump designed for Hyundai wheel loaders HL770-7A and HL770-9S. This fixed-displacement double pump delivers high flow and stable pressure to meet the demands of the working equipment and steering systems. We specialize in the R&D and manufacturing of high-pressure pumps, motors and valve blocks. Our products offer 100% drop-in interchangeability with genuine Hyundai and compatible Parker Denison-style units and undergo 100% simulated operating-condition testing. Precision machining and high-quality materials ensure stable operation under high-pressure and high-load conditions for construction machinery main hydraulic systems.

Technical Specifications 

(Based on Hyundai official machine data and compatible technical information; theoretical values excluding efficiency and tolerances)

• Model: 31LB-00400 / 31LB00400
• Compatible machines: Hyundai HL770-7A, HL770-9S wheel loaders (main pump)
• Type: Fixed-displacement double vane pump
• System pressure: approx. 210 kgf/cm² (approx. 20.6 MPa / 210 bar)
• Peak pressure: Higher intermittent values possible (compatible listings up to 28 MPa)
• Flow reference: Main pump flow approx. 396–425 L/min (depending on speed)
• Speed range: approx. 600–3600 r/min
• Control: Fixed displacement, double configuration (working equipment + steering/auxiliary)
• Mounting & ports: Original-equipment matching flange and shaft (splined shaft common)
• Approximate weight: 46 kg
• Other: Cast-iron housing, suitable for high-load construction machinery conditions

Key Technical Advantages

1. Double fixed-displacement design: Simultaneously serves working equipment and steering/auxiliary circuits in a compact, high-efficiency package.
2. High-pressure stability and low noise: Precision vane-to-stator geometry delivers smooth, quiet operation and long service life.
3. High-reliability materials and processes: Quality cast-iron housing and wear-resistant components withstand harsh construction environments.
4. 100% drop-in interchangeability and simulated-condition testing: Overall dimensions, mounting interfaces and performance curves match genuine units exactly for direct replacement. Every unit undergoes 100% simulated operating-condition testing to verify pressure, flow, efficiency and sealing performance.
5. Strong compatibility: Highly compatible with Parker Denison-style double vane pumps for easy maintenance and replacement.

Application Areas

• Hyundai HL770-7A / HL770-9S wheel loader main hydraulic systems
• Construction machinery working equipment and steering circuits
• Loaders and similar equipment requiring high-flow fixed-displacement double oil supply
• Heavy mobile equipment hydraulic power sources

Expert Maintenance Tips

• Before installation, confirm shaft type and flange match the host machine. Ensure adequate suction line diameter and proper sealing to avoid cavitation.
• Use anti-wear hydraulic oil with cleanliness meeting ISO 4406 18/16/13 or better; maintain suitable viscosity at operating temperature. Run at low speed during cold starts.
• Regularly check system relief valve setting (approx. 210 bar) to avoid over-pressure damage to the pump.
• When replacing internal components, maintain strict cleanliness; perform air bleeding and low-pressure test run after assembly.
• Perform preventive inspections every 2000–4000 hours depending on duty cycle; monitor noise, temperature and any flow changes, and service promptly.