The objective of the paper was to analyse the change of the disturbance amplitude Pmax of the system under pressure depending on the total stream of liquid flow in the milk pipeline, which was set Q mr and its impact on the changes of average under pressure of suction pss, amplitude of suction under pressure aps, amplitude of massage under pressure apmin the measuring milking apparatuses (of the selected makes). The measuring apparatus was connected to the installation of a pipeline milking machine in the first stand tap (towards the final unit). The set streams of liquid flow from milking apparatuses were accepted Q m within 0 to 8 l·min-1. The research was carried out at regular operation of the milking machine (system negative pressure oscillations- cyclic) and after introducing disturbance (negative pressure oscillations - irregular). For comparison of the milking machines, products of four companies were selected. The same machines of a given company (6 items) were enclosed to the milking machine installation on the pipeline. Changes of the above mentioned parameters of milking in the measuring apparatus were determined and presented depending on the maximum amplitude of disturbance P m. Models describing changes of milking parameters in the milking apparatuses of the selected companies, which are the subject of the separate article were developed.