Abstract
The purpose of this research is to redesign the compressed air driven hydraulic motor system which is designed in the former research and to improve the control method and system efficiency. In this research, intake pipe system is rearranged. A new mode of operation to recover residual pressure is used. This recovering mode can boost the system to improve the system efficiency. Finally, we measure system efficiency in expand mode and isobaric mode to find out the optimum operating parameters.