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Lift Tables

Why won't the lift go up?

  1. The load is too heavy - Check the actual weight of the load. The rated capacity of the lift is on the table skirt.
  2. The motor is not running - Check the main disconnect switch, the fuse(s) and the wiring to the motor.
  3. The hydraulic oil level may be low. - When the lift table is raised, the oil should be 3/4" of an inch above the bottom of the tank. (The exact level varies with different models, especially on models with tanks that tip as the lift elevates.) Use a dipstick to check the oil level.
  4. Your lift is equipped with an optional limitswitch - The lift may have reached this upper limit. If the switch is out of adjustment, the lift may not be able to raise completely. Readjust the switch if necessary.
  5. Your lift is wired incorrectly - On a lift with a three-phase motor, the motor may be running backwards. If the motor has been wired correctly, the lift should start moving 2 or 3 seconds after you press the UP button. If it doesn't, try reversing any two electrical leads.
  6. The motor voltage may be too low - Check the voltage at the starter when the motor is under load. The supply voltage should be within +/-10% of the rating.
  7. On a lift with an external power unit, the tank vent may be plugged - You must remove the solid plug from the tank and insert the vent plug. The vent line must be clear.
  8. The suction filter may be clogged.
  9. A vacuum leak may be allowing air into the suction line, causing cavitation (loss of suction) in the pump - Check all fittings in the suction line, and tighten or replace as necessary.

The lift raises, but will not hold a load.

  1. The check valve may be leaking. Dirt on the valve seat will prevent the valve from closing fully. The check valve is mounted in the pump housing. Remove the check valve cap and inspect the valve for dirt or metal chips which may be preventing it from closing. You may be able to restore the seal by lightly rapping the ball into the seat using a 1/4" diameter rod and a small hammer.
  2. The down-valve may be energized. While the lift is holding a load, the down-valve should be de-energized and fully closed. Check the solenoid in the valve with a voltmeter. The valve must also be clean and free to operate. To check this, remove the solenoid and then the valve. Look for dirt or metal chips that could block the valve action. Clean the valve plunger with kerosene, then blow clean with compressed air. The expansion nut that holds the solenoid should be finger tight only!
  3. The cylinder may be leaking. Look for oil on the cylinder rod(s) and in the vent line. (This may also occur if the oil tank has been over-filled.) If you find oil in either place, and the tank is not over-filled, the cylinder should be repacked.

Why doesn't the lift lower?

  1. The down-valve may be de-energized. When the lift is lowering, the down valve should be energized and fully open. Check the solenoid in the valve with a voltmeter. The valve must also be clean and free to operate. Remove the solenoid, then the down-valve. Look for dirt or metal chips that could block the valve action. Clean the valve plunger with kerosene, then blow it clean with compressed air. The strainer screen over the lower part of the plunger must be clean. Before reassembly, depress the plunger by hand several times to be sure it moves freely. The expansion nut that holds the solenoid should be finger tight only!
  2. The flow control may need to be adjusted. The flow control must be partially open to allow the oil to return from the cylinder(s). It is important that you follow these steps when adjusting the flow control:

    • Raise the lift table completely, and insert the Maintenance Devices.

    • If you want the lift to lower more slowly, turn the control clockwise up to 1/4 turn at a time. If you want the lift to lower more quickly, turn the control counterclockwise up to 1/4 turn. Don't move the control more than 1/4 turn at a time.

    • Remove the Maintenance Devices and check the speed as the table lowers.

    • Every time you want to change the adjustment again, raise the table top again and insert the Maintenance Devices.