New power steering put in

I just had a power steering put in my Ford Taurus
have been broken down for about 2 years I actually
had a professional mechanic put it in and it still
made whining noises a lot after I got it back and I
was told that you get that a lot with four Tauruses
they're still going to make some noise so my
question is is it normal for you to have to
consistently replace the power steering fluid when
it starts getting louder? Because I've also noticed
that when it starts making a louder noise than
normal I'll check the fluid in it seems to be low.