It is probably a good idea to also replace the power steering filter while you have the top off.
If it hasn't been done in a while, it might be a good idea to totally change the ps fluid.
These two things will help ensure a long-life of the pump and compenents.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)