FIELD: method for drying of inner surfaces of hydraulic systems including branched pipe-lines with dead end areas, vessels, units, and assembles with a developed surfaces before checking them for leak-proofness. SUBSTANCE: the inner surfaces of hydraulic system preliminary dried up of unbound moisture are blown down with hot compressed air at a constant maximum allowable temperature for hydraulic system and a pressure corresponding to the operating pressure up to the moment of establishment of a constant value of air temperature at the outlet of the hydraulic system, after that the outlet of hydraulic system is blanked off, the hydraulic main lines of the closed hydraulic system are filled with air with blow down parameters up to establishment of the operating pressure in the whole hydraulic system, endurance is a accomplished at the operating pressure up to saturation of bound moisture in the micropores and microcracks of the hydraulic system with gas, then the hydraulic system is evacuated, after which the processes of blow-down, filling and endurance of the hydraulic system at its operating pressure with hot air, as well as vacuum processing, are cyclically repeated until the pressed value of moisture content of the hydraulic system is attained. EFFECT: enhanced efficiency of the process of drawing of articles before they are checked for leak proofness by dispersing of bound moisture in micropores and microcracks of the hydraulic system by the gas liberated from it at cyclic repetition of the processes of blow-down, filling with endurance of the hydraulic system at its operating pressure with hot air as well as vacuum processing. 1 cl, 1 dwg
