SUMMARY
In this paper the possibility of phase trajectory use in detecting of axial piston pump damage was presented. The wear of main part of pump elements such as: rotor and swash plate have been studied. The Phase trajectories were estimated from vibration signal measured on pumps body in third directions. In order to get quantitative specification of analyzed trajectory Atpi parameter was introduced. At the and the relation between Atpi parameter and the wear of the pumps parts have been set.