A method for detecting manufacturing defects of hydraulic dampers, especially hydraulic shock absorbers described herein applies a measurement procedure consisting of a set of computational tasks performed in a specific sequence with the use of measuring computer in order to record a vibration acceleration signal of mechanical vibrations of a piston rod of a hydraulic damper displacing by a forcing actuator, while the vibration acceleration signal is obtained by an accelerometer , moreover the method comprises two phases, wherein phase one consists of subsequent operations of the measurement procedure, followed by automatic pre-processing of the vibration acceleration signal, processing of the vibration acceleration signal, processing of the signal using an FFT algorithm, determination of statistical characteristics of the spectrum, such as mean, variance and standard deviation, followed by the determination of the values of upper and lower boundary characteristics for each of the n frequency intervals of the spectrum domain, whereas phase two includes, in sequence, the measurement procedure, automatic pre-processing of the vibration acceleration signal, additional processing of the vibration acceleration signal, processing of the signal using an FFT algorithm, determination of the values of upper and lower number of exceedance of boundary characteristics, comparison of the sum of the number of the upper and lower exceedance of boundary characteristics with the corresponding limit values and, based on that, indication of the classification result in the form of two conditions: fit or unfit, wherein the measurement procedure consists of the following steps: first, the hydraulic damper is placed on a fixing plate and fixed in place; then the forcing actuator (9a-d) moves down at a speed controlled by the control system and attains a position in which the accelerometer fastened to the piston rod of the forcing actuator makes contact with the end of the piston rod of the hydraulic damper, after that the movement at the speed controlled by the control system is continued until the forcing actuator attains a set outward working position h TH , whereas the vibration acceleration signal is recorded throughout the duration of the outward movement of the piston rod of the forcing actuator, characterized in that the hydraulic damper is fixed in place during the measurement procedure by clamping it with a hydraulic damper blocking actuator , and in that the hydraulic damper is positioned so that the longitudinal axis of the hydraulic damper piston rod is directed upwards, whereby the vibration acceleration signal is recorded by the accelerometer which is secured to the end of the piston rod of the forcing actuator, and by using standard sample hydraulic dampers in the phase of determining boundary characteristics, said standard sample hydraulic dampers being of a design identical to that of the tested hydraulic damper; and in that automatic clipping of the vibrational acceleration signal is effected in the time domain by the range of t 0 -t s , wherein the t s point is determined by the instant the accelerometer comes into contact with the end of the hydraulic damper piston rod, while t 0 is determined by the instant the piston rod of the forcing actuator is in its upper end position, and in that in order to determine the boundary characteristics an iteratively determined maximum correction factor of the standard deviation a max and adjusted standard deviation σ c j are used. <EOS>