Essential Tips for System Venting When Replacing Cartridge Valves in Hydraulic Excavators

Why Proper System Venting is Crucial After Cartridge Valve Replacement

Air trapped in Hydraulic Systems can cause:

• Spongy or unresponsive controls due to compressible air bubbles

• Overheating from poor fluid circulation

• Premature wear in the main relief valve for hydraulic excavator

• Pressure fluctuations, leading to inefficient pump operation

To avoid these issues, follow these essential steps for effective air removal.

Step-by-Step Guide to Venting Hydraulic Systems After Valve Replacement

1. Pre-Installation Preparation

• Ensure the hydraulic system is depressurized before removing the old cartridge valve.

• Clean the valve cavity to prevent contamination.

• Inspect the new hydraulic excavator pressure relief valve for any defects before installation.

2. Proper Installation of the New Cartridge Valve

• Tighten the valve to the manufacturer’s recommended torque to avoid leaks.

• Use thread sealant (if applicable) but avoid blocking fluid passages.

• Verify that O-rings and seals are properly seated to prevent air ingress.

3. Initial System Pressurization and Venting

• Slowly fill the hydraulic reservoir to prevent air entrapment.

• Start the engine at low RPM and allow the pump to circulate fluid.

• Actuate hydraulic functions (e.g., boom, bucket) in short strokes to push air toward the reservoir.

4. Cycling the Main Relief Valve for Air Removal

• The main relief valve for hydraulic excavator should be cycled multiple times to purge trapped air.

• Gradually increase system pressure while monitoring for abnormal noises or vibrations.

• If the hydraulic excavator overflow valve exhibits chattering, air may still be present—repeat Venting steps.

5. Final System Check and Performance Verification

• Run the excavator under normal load conditions to ensure smooth operation.

• Check for leaks around the newly installed cartridge valve.

• Monitor hydraulic fluid temperature—excessive heat may indicate remaining air pockets.

Common Mistakes to Avoid During System Venting

❌ Rushing the Process – Incomplete Venting leads to lingering air pockets.
❌ Overpressurizing Too Quickly – Can damage seals in the hydraulic excavator pressure relief valve.
❌ Ignoring Noises – Bubbling or knocking sounds indicate trapped air.
❌ Skipping Load Testing – Systems may seem fine at idle but fail under real working conditions.

Longerfa’s High-Quality Excavator Relief Valves for Optimal Performance

As a leading manufacturer of hydraulic excavator relief valves, Longerfa ensures:
✔ Precision-engineered hydraulic excavator overflow valves for consistent pressure control
✔ Durable main relief valves designed for long service life
✔ Reliable and durable excavator overflow valve solutions for harsh working conditions

For top-tier hydraulic components, explore our product line:
🔗 Hydraulic Excavator Relief Valves – Longerfa

Conclusion

Proper bleeding after cartridge valve replacement is essential for maintaining hydraulic excavator efficiency. By following these steps, operators can prevent air-related issues in hydraulic excavator pressure relief valves, overflow valves, and other critical components.

Trust Ningbo Longerfa Hydraulic Co., Ltd for high-performance, reliable and durable excavator overflow valve solutions that withstand demanding conditions.

By adhering to these best practices, equipment owners can ensure smooth hydraulic operation, extend component lifespan, and minimize costly downtime.

Ningbo Longerfa Hydraulic Co., Ltd – Innovation in Hydraulic Control Solutions
📍 Visit our website for more high-performance hydraulic excavator valves!