power steering

hey everyone one more question while i was wout cruising today i noticed how whenever i turned my steering wheel to the right or left it made the hydraulic sort of buzzing noise, or it could be called a grinding but i dont know what it is, i assume it is my power steering because it only happened when i turned the wheel, has anyone else had this happen? and if so how should i fix it? or is it nothing at all

thanks again fellow stangers
jerry