The interplay between the nuclear activity and the interstellar medium (ISM) of galaxies plays an important role in their evolution: the gas accreting onto the dormant supermassive black hole turns it into an active galactic nucleus (AGN) and the ensuing activity is believed to starve the host galaxy of the fuel needed to form stars. The contribution of radio-loud AGN to this feedback effect is yet to be well understood. In order to understand the impact of radio AGN, we need to study the jet-ISM interaction in detail in sources covering a wide range of parameters such as age/morphology, radio power. In this context, I will present a detailed study of a very young (5000 years old) radio source, 4C31.04. Our pc-scale atomic gas observations and kpc-scale molecular gas observations combined show the presence of a strong coupling between the radio jets and the cold gas resulting in significantly disturbed gas in the nuclear region, in agreement with various assumptions of numerical simulations while also posing challenges to the models trying to explain the incidence of cold gas in such extreme environments.