Rafeeki, The way you fill up your air retract is you need to have another robart fill valve and fill chuck connected together with a piece of air line tubing. Then you put the fill valve, which has same dimensions a tire valve into the air pump. Then screw the fill chuck in to the fill valve on your plane and turn on the compressor until the desired pressure is achieved. Good luck. You will need robart part number #168 Fill Valve & Fill Chuck kit. Connect both of these parts together with a piece of air line tubing. Good luck.