this might be a stupid noob question but i gotta learn somewhere .Is it ok to use a s5 power steering pump in an s4?

 

As far as I know it will hook up just fine. You will want to read up about the difference between speed sensitive PS and rpm sensitive PS. It may be PS ECU controlled though.

In reality though, go for no power steering. Once you do it you will never look back.

 

I'm fairly certain as well, that if you just swap out the mechanical pump itself, it'll work fine. Leave the electrical parts S4.

 

I did this and its been working great. Everything slaps right in. Before you install the S5 change the lines to some new ones so that you dont have to in the future.