How to exhaust air from the two-pillar lift

During the operation of the newly installed double-column lift, if the trembling phenomenon occurs during the lowering process, it means that there is air inside the cylinder. How can we discharge the air from the cylinder?

Now the hydraulic system is equipped with exhaust plugs, which are located at the top of the oil cylinder (as shown in the figure below). We should first lift the lifting platform, but do not exceed the safe position, so that the oil cylinder is in the internal pressure state. At this time, use a wrench to loosen the top plugs, do not screw them out completely. At this time, you will hear the sound of exhaust. When there is oil coming out, it basically means that all the air is discharged, and then tighten the plugs. (Pay attention to protect the O-ring above the plug)

If shaking still occurs, please repeat the above operation until the equipment can run at an even speed.