What to consider before you plan the internal thread screwed onto the external thread of the damper for example, you must first solve a knurled nut (at the pump). This ensures that air does not flow out. If you have done this, you screwed connection on it and can inflate very quickly, the pressure remains constant as not vary. Once you're done NOT solve the big screw, but only the knurled nut, otherwise the air escapes. It may be that there is a very short hisses bisl, which is however not the air from the shock, but the residual pressure from the pump, so do not worry;)
I would recommend these high-pressure pump safely. 40 is not just a little money, but a good investment.