Labyrinth seals are the most widely used non-contact-type turbine seals. The main design concern is to prevent the seal rub with the stator in the range of operating conditions and to control the system rotordynamics. This work aims at experimentally evaluating the effect of thermal growth of labyrinth seal on the leakage flow rates and effect on vibration characteristics of the system. An experimental seal test rig for teeth on rotor (TOR)-type straight labyrinth seal with four flat tip teeth has been developed. Constant clearance between seal and stator is maintained and tested at different speeds and temperatures by varying the inlet air pressure. Leakage results are compared for the seal for the range of operating conditions and for a given seal radial clearance. In addition, vibration data are measured at various locations to understand the influence of seal on the vibration characteristics of the rotor system. It is seen that flow leakage rate and vibration of system are influenced by the pressure difference and the temperature. © 2021, Springer Nature Singapore Pte Ltd.