Frequent Main Pump Failures on Daewoo DH370 Excavators? Read This Maintenance & Replacement Guide

1. Common Symptoms of Main Pump Failure

Daewoo DH370 excavators frequently encounter main pump issues under continuous high-load operations, such as:

• Slow or weak digging motion

• Unstable or insufficient hydraulic pressure

• Frequent overheating alarms

• Vibrations or failure in swing and travel operations

• Increased fuel consumption and reduced efficiency

2. Key Wear Points in the Hydraulic Pump

The DH370’s hydraulic pump—typically a large-displacement axial piston unit—often experiences wear in:

• Piston and Cylinder Block: Continuous friction reduces volumetric efficiency

• Valve Plate (Swash Plate): Worn surfaces cause internal leakage and pressure loss

• Drive Shaft: Seal failure or bearing wear leads to energy loss and abnormal noise

• Control Valve Assembly: Reduced response causes sluggish movements

3. Recommended Repair and Replacement Strategy

• Diagnose First: Use a pressure gauge and flow meter to assess output and pinpoint faults

• Replaceable Components:

  • Piston assembly

  • Valve plates (L/R)

  • Center pin, disk spring, retainer, and spacers

• Replacement Cycle:

  • Standard conditions: Every 4000–6000 hours

  • Harsh environments: Check every 3000 hours

• Suggested Upgrades:

  • Consider Rexroth A8VO160 as a high-precision, long-life replacement compatible with DH370 systems

4. Preventive Maintenance Tips

• Replace hydraulic oil and filters every 1000 hours

• Regularly monitor oil temperature, pressure, and pilot signal

• Avoid continuous overload operation

• Warm up the pump by idling for 3–5 minutes before work