1. Introduction

This manual provides procedures for performing air purge operations on the MHP system and maintaining the check valve. Proper maintenance ensures efficient actuator operation and prevents pressure loss.

2. Air Purge Procedure

1. Remove the Oil Plug:

   • Detach the oil plug before initiating actuator operation.

2. Actuator Operation:

   • Perform Open/Close (OP/CL) cycles to remove air from the system.

3. Sustained Power Supply:

   • At full position, continue applying power for 2 to 3 minutes to discharge trapped air inside the tank.

4. Repeat the Process:

   • Repeat the procedure 2 to 3 times until air is fully removed.

5. Reassemble the Plug:

   • After air removal, reinstall the oil plug securely.

⚠️ Note: Ensure lost oil is replenished after the air purge process.

3. Additional Air Removal (If Necessary)

• If actuator slippage occurs even after performing the air purge, connect a by-pass hose to the actuator’s Emergency Connector and remove residual air.

4. No Pressure Output - EHPP System

If the EHPP system fails to generate pressure, follow the steps below to inspect and maintain the check valve.

1. Check Valve Overhaul and Reassembly

• If there is no pressure output, inspect the check valve for contamination or malfunction.
• Disassemble the check valve assembly carefully to prevent component damage.

2. Removing the Check Valve

• Detach the Power Pack Unit:

  • Remove the power pack unit from the actuator.
  • ⚠️ Do not disconnect the cable to avoid electrical disconnection errors.
  • 

• Remove the Motor Part:

  • Detach the motor section for easier access to the check valve.
  • 

• Extract the Check Valves Using a Magnet:

  • Insert a magnet tool into the designated ports to carefully remove the check valves.
  • This prevents scratching or damaging the valve components.
  • 

3. Cleaning the Check Valve

• Disassemble the check valve carefully, ensuring no parts are lost.
• Wipe the inside of the check valve thread groove using a clean, lint-free cloth (rag).
• Remove any foreign particles, as even minor contamination may cause operational failure.

4. Suction Hose Inspection

• Separate the Pump and Tank:
  • Keep the pump and tank in a vertical position to prevent unnecessary oil loss.
• Check for Loose or Damaged Suction Hose:
  • Ensure that the suction hose is firmly connected and free from cracks or damage.

⚠️ Caution:

• When reassembling the check valve, ensure that all components are returned in the correct order to avoid operational failure.
• Confirm proper alignment of the motor and power pack unit before completing reassembly.

5. System Reassembly Considerations

• Double-Acting and Single-Acting Configurations:

  • Follow specific reassembly guidelines based on actuator type.

• Post-Maintenance Checks:

  • Ensure proper movement inside the check valve by manually pushing it from both directions several times.
  • Verify that oil levels are restored before operating the system.

6. Troubleshooting Summary