This article examines the possibility of measuring lift maintenance through
analysis of used hydraulic oil. Hydraulic oils have proved to be a reliable indicator for the
maintenance performed on elevators. It has also been proved that the end users or the
maintenance personnel do not always conform to the instructions of the elevators’
hydraulic machine manufacturer. Furthermore, by examining the proportion of the metals,
an estimation of the corrosion and the wear resistance of the joined moving parts can be
observed. Additionally, the presence of chlorine and calcium in hydraulic oils demonstrates
their function in a highly corrosive environment.