Pump motor runs, Jack(s) Do Not Extend

  • Updated

When the pump motor runs but one or more of the jacks do not extend complete the following steps.

Check for power and ground to the coils:

Using a test light or multimeter, go to the corresponding extend coil for the jack that is not operating and have a helper press the extend switch for that jack. While the switch is being pressed, verify that you are getting a good ground, and 12 volts to the coil of the extend valve by back probing the wires going into the coil.

Section 1

  • If you are getting ground and 12 volts to the coil, then have a ferrous metal coat hanger near the coil and see if you have a magnetic pull.
    • If you do not feel a magnetic pull there, replace the coil and retest the system.
    • If you have a magnetic pull then the coil is good, and the problem is hydraulic related, and you will need to go to Section 3.

Section 2

  • If you are not getting 12 volts to the extend valve coil then complete the following steps.

    • If no voltage is found on the coil when the extend switch is being pressed for that jack, test at the back of the switch to see if you have 12 volts into the switch.
    • If there is 12 volts present, press the switch and see if you have 12 volts out of the switch.
    • If you have 12 volts out of the switch then follow the wires back to the controller. Refer to the wiring schematics.
    • Test on each side of every connection as you follow the wires through. If you find a connection that is failed replace the connection and retest.

Section 3

  • Check for an extend valve failure by completing the following steps.

    • The affected extend valve can be exchanged with a valve from a jack that is working properly.
      • If the problem follows the affected valve then replace the valve.
      • If the problem does not follow the affected valve then the extend valve is not failed.
    • If all of above checks out, then reinstall the valves back into the original position and retest.
    • If the jack works after reinstallation of the valve then there may have been some debris in the system, or the valves or nuts may have been over-torqued.

It would be recommended to install a new extend valve as there may be damage that will cause the same issue again later.

Torque values for valves and coil retaining nuts:

    1. Valve: 144 inch pounds
    2. Coil Retaining Nut: 36 inch pounds


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