Quick Troubleshooting Guide for Komatsu PC120-6 Unloading Valve Failure Leading to Weak Performance Komatsu PC120-6 Excavator Hydraulic System – Key Component: Unloading Valve (723-30-56100)

Symptoms of a Faulty Unloading Valve in Komatsu PC120-6

Before diving into diagnostics, recognize these key signs:

• Reduced hydraulic power – Slow or weak movements in digging, lifting, or swinging.

• Overheating Hydraulic System – Excessive heat due to pressure leaks.

• Unstable operation – Jerky or inconsistent hydraulic functions.

• Increased fuel consumption – The engine works harder due to hydraulic inefficiency.

If these symptoms appear, inspect the unloading valve 723-30-56100 immediately.

Step-by-Step Troubleshooting Method

1. Check Hydraulic Fluid Level & Quality

Low or contaminated hydraulic fluid can mimic unloading valve failure.

• Ensure the fluid is at the correct level.

• Look for discoloration, bubbles, or debris, indicating contamination.

• Replace the fluid and filter if necessary.

2. Inspect for External Leaks

• Examine hydraulic hoses and connections near the unloading valve.

• Look for oil leaks, which may indicate seal failure or valve damage.

3. Test Hydraulic Pressure

Use a pressure gauge to measure system pressure:

• Standard pressure for Komatsu PC120-6: ~320 kg/cm² (varies by model).

• If pressure is below specification, the unloading valve may be stuck open or damaged.

4. Remove & Inspect the Unloading Valve (723-30-56100)

• Locate the unloading valve in the hydraulic control block.

• Disassemble carefully and check for:

  • Worn or broken springs – Affects pressure regulation.

  • Contamination (metal shavings, sludge) – Blocks valve movement.

  • Damaged seals or O-rings – Causes internal leaks.

*Inspecting the Komatsu PC120-6 Unloading Valve (Part No. 723-30-56100) for Wear & Contamination*

5. Clean or Replace the Unloading Valve

• If contamination is found, clean the valve thoroughly with hydraulic solvent.

• If components are worn or damaged, replace the Komatsu PC120-6 unloading valve 723-30-56100 with a high-quality part from Ningbo Longerfa.

6. Reassemble & Test Operation

• Reinstall the valve and refill hydraulic fluid.

• Start the machine and test hydraulic functions.

• Monitor pressure and temperature to confirm normal operation.

Why Choose Ningbo Longerfa’s Replacement Unloading Valve?

At Ningbo Longerfa, we manufacture durable and precision-engineered hydraulic valves, including the Komatsu PC120-6 unloading valve (723-30-56100). Our products offer:

• Exact OEM specifications – Ensures compatibility and performance.

• High-quality materials – Resistant to wear and corrosion.

• Rigorous testing – Guarantees reliability under heavy-duty conditions.

Conclusion

A failing Komatsu PC120-6 unloading valve (723-30-56100) can severely impact excavator performance. By following this quick troubleshooting guide, operators can diagnose and resolve issues efficiently. For long-term reliability, always use genuine-quality replacement parts from trusted manufacturers like Ningbo Longerfa Hydraulic Valve Co., Ltd.

For inquiries about the Komatsu PC120-6 unloading valve 723-30-56100, contact us today!