I seemed to have a leak from the power steering unit. Everything looks solid, but there is a slow leak - only seems to appear when the ignition is on.

Anyone ever replaced these?

 

do u see a leak or theres a sound when you turn the steering wheel?

 

If by power steering unit you mean rack, your not looking at a do it yourself job. Its a real pain. Its almost like they started with the rack and built the car around it. In the rs6 you actually have to remove the entire engine. If you mean the pump, thats a much easier job. You wont need any special tools. Its slightly more difficult on the 2.7 due to the intake hoses, but its doable.