Hydraulic pump for Hyundai R210LC-9

Product & Spec Guide

Hyundai R210LC-9 hydraulic pump

OEM replacement main hydraulic pump assemblies for 21-ton crawler excavators

OEM Fit
1-Year Warranty
Europe-Wide Shipping

The Hyundai R210LC-9 (including standard Robex 210 and R210LC-9 series) is a highly popular and productive 21-ton class crawler excavator, built for high-production trenching, earthmoving, truck loading, and utility construction. Renowned for its fuel economy, smooth controls, and high digging force, the machine relies on its high-pressure hydraulic circuit to execute all major work cycles. The heart of this circuit is the **main hydraulic pump assembly**, which converts the mechanical output of the Cummins diesel engine into hydraulic fluid power.

Continuous heavy load cycles will eventually lead to component wear. If your excavator suffers from slow joystick response, engine stalling, uneven travel tracking, or loud whining sounds from the pump compartment, your main pump is likely worn out. We provide **high-performance, OEM-quality replacement main hydraulic pumps** for the Hyundai R210LC-9, engineered to restore factory-specification digging power, speed, and overall jobsite productivity.

In need of replacement parts? View all spare parts and options for Hyundai machines →

1. OEM Compatibility & Part References

To ensure a direct, plug-and-play fit without modifying hydraulic hose connections or control linkages, our replacement pumps are cross-referenced and fully compatible with these key OEM and manufacturer references:

31QB-10100 / 31QB-10101 / 31QB-10102 / 31QB-10103 / 31QB-10104: Genuine Hyundai OEM part numbers representing design revisions for the R210LC-9 pump assembly.
31Q6-10010: Primary Hyundai assembly number for R210 series hydraulic pumps.
K3V112DT / K3V112DTP: Kawasaki high-performance swashplate-type tandem axial piston pump used as original equipment.
K3V112DTP1H9R-9P12: Exact Kawasaki manufacturer model reference configured to Hyundai factory specifications.

If the identification nameplate on your current main pump displays any of these references, our replacement unit will fit perfectly.

2. Technical Specifications

This technical table outlines the mechanical parameters, operating pressure limits, and regulator configurations for the Hyundai R210LC-9 main hydraulic pump:

Machine Class

21.0 Metric Tons (Hyundai R210LC-9 Crawler Excavators)

Pump Configuration

Tandem axial piston double pump (two separate variable-displacement groups on a single shaft)

Displacement (cc/rev)

112 cc/rev x 2 (Kawasaki K3V112DTP)

Rated Operating Pressure

34.3 MPa (343 bar / 4,980 PSI)

Maximum Peak Pressure

37.8 MPa (378 bar / 5,480 PSI) with Power Boost engaged

Max Discharge Flow

2 x 220 L/min (2 x 58.1 gpm)

Pilot System Pump

Integrated fixed-displacement gear pilot pump (approx. 20 L/min, 5.0 MPa / 50 bar output)

3. Pump Assembly & Core Components

The tandem pump assembly utilizes several critical mechanical and hydraulic systems to govern oil flow and system pressure:

Tandem Piston Groups

Two inline cylinder barrels containing nine pistons each. Rotating cylinder groups draw oil from the intake port and push it into the control valve block.

Swashplate Cradle & Servo Pistons

The angle of the swashplate determines the piston stroke length. Servo pistons adjust this swashplate angle dynamically to stroke or destroke the pump based on operator demand.

NFC Regulators

Negative Flow Control (NFC) keeps the pump destroked to minimum flow when joysticks are in neutral, saving fuel. Engaging the controls drops the NFC return pressure, prompting the regulators to stroke the pump for immediate flow.

Horsepower Overrides

Mechanical torque-limiting spring packs prevent the engine from stalling. If hydraulic pressure spikes under heavy digging, these overrides destroke the swashplate automatically to protect the engine torque curve.

4. Failing Pump Diagnostics & Symptoms

Main hydraulic pumps operate under extreme pressure and thermal stress. Watch for these common indicators of pump deterioration:

Loss of Cycle Speed Under Load

Sluggish cylinder movement (especially once the hydraulic oil warms up and thins) points to internal volumetric slippage. Worn piston shoes or scratched cylinder face plates allow high-pressure oil to slip into the case drain rather than working the cylinders.

Engine Bogging or Stalling

If the engine bogs down as soon as you pull a joystick, the regulator spool valves may be stuck. They fail to destroke the swashplate when pressure spikes, overloading the engine.

Metallic Screeching or Whining

Bearing damage or cavitation (imploding air bubbles in the oil) creates a distinct, loud whining noise. Running a pump with this condition leads to catastrophic failure.

Stiff Joystick Response

If the pilot gear pump mounted on the back of the main assembly wears out, pilot circuit pressure will drop, making control joysticks heavy and sluggish.

CRITICAL REQUIREMENT: Flushing the Hydraulic System
When a hydraulic main pump suffers a catastrophic failure, it releases millions of microscopic brass and steel particles into the hydraulic circuit. These particles travel through the control valves, cylinders, and travel motors. If you install a replacement pump without thoroughly flushing the hoses, cleaning the main reservoir tank, and replacing the suction and return filter elements, the remaining debris will flow back into the new pump, destroying its pistons and valve plate within a few hours of operation.

Frequently Asked Questions About Hyundai R210LC-9 Pumps

How do I verify if this main hydraulic pump fits my Hyundai R210LC-9?

Our replacement pump is fully compatible with Hyundai OEM references 31QB-10100, 31QB-10101, 31QB-10102, 31QB-10103, 31QB-10104, and 31Q6-10010. It houses the Kawasaki K3V112DTP tandem axial piston pump (specifically K3V112DTP1H9R-9P12) and fits all standard R210LC-9 crawler excavators in the 21-ton class.

Does this pump assembly include regulators and pilot pump?

Yes. The pump is delivered as a complete, pre-assembled factory unit. It includes both variable displacement piston groups, the pilot gear pump, and the negative flow control (NFC) regulators pre-calibrated to factory specifications for instant plug-and-play installation.

What are the common symptoms of a failing main pump on a Hyundai R210LC-9?

Common symptoms include sluggish boom or bucket speeds (especially when hydraulic oil heats up), engine bogging/stalling under load (failed regulators failing to destroke), straight line travel drift, and loud whining or grinding noises originating from the pump bay.

Why is flushing the system critical when replacing this pump?

If a pump suffers a mechanical failure, it releases millions of microscopic brass and steel particles into the hydraulic oil. Installing a new pump without flushing the lines, cleaning the reservoir tank, and replacing return and suction filters will carry this debris straight back into the new pump, destroying it within hours.

5. Related Technical Guides & Internal Link Building

To keep your excavator fleet running at peak performance, explore our library of machine guides and maintenance articles. If you are diagnosing tracking issues, consult our detailed guide on tracking speed differences on excavators or read about identifying the signs of a bad final drive. If you need to separate pump issues from travel motor issues, refer to our final drive troubleshooting guide, and learn the fundamental differences in our article on final drives vs. travel motors.

For detailed information on pump mechanics, read about the principles of hydraulic main pumps or see our technical analysis on the function of a hydraulic main pump. When it comes to replacement, check our walk-throughs on how to change a final drive and how to repair a final drive. Make sure to get precise measurements with how to measure a final drive correctly, and prevent future failures by reading our final drive maintenance guide.

If you also operate other machines in your fleet, you may find our other machine-specific final drive optimization guides helpful: view our guides for the Hyundai R290NLC-7, the Case CX210B, the Volvo EC210B, the JCB JS200LC, the Hyundai R140LC-7, the Daewoo Solar 130LC-V, and the Hitachi ZX210LC-3 final drives, and the Kobelco SK350LC-8 main hydraulic pump, the Doosan DX255LC main hydraulic pump, the Volvo EC210C main hydraulic pump, the Case CX210 main hydraulic pump, the JCB JS160NLC main hydraulic pump, the New Holland E200SR main hydraulic pump, the Case CX330 main hydraulic pump, the Hyundai R290LC-7A main hydraulic pump, the Hyundai R140LC-7A main hydraulic pump, the Kobelco SK210LC-6 main hydraulic pump, the New Holland E215 main hydraulic pump, the Caterpillar 320D main hydraulic pump, the Hyundai R320LC-7 main hydraulic pump, the Caterpillar 312C main hydraulic pump, the Kobelco SK210LC-10 main hydraulic pump, the Volvo EC460B main hydraulic pump, the Volvo EC360B main hydraulic pump, the Volvo EC290B main hydraulic pump, the JCB JS220LC main hydraulic pump, the Kobelco SK200LC-8 main hydraulic pump, the New Holland E215B main hydraulic pump, and the Hyundai R290NLC-7 main hydraulic pump.

Browse our extensive hydraulic spare parts inventory. If you need direct technical assistance or would like to request a quote, fill out our quote form below or email our team in Horsens, Denmark at info@mecatra.com.

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