[Dmitry at Pelican Parts]

Hello and welcome to the forum! It could be the power steering pump has gone bad - I'm attaching a link to a DIY tech article from our site on this replacement procedure. Other members may also chime in with their expertise. Hope this helps you a bit and best of luck!

https://www.pelicanparts.com/techarticles/MINI/47-SUSPEN-Power_Steering_Pump_Replacement/47-SUSPEN-Power_Steering_Pump_Replacement.htm