Can any one help?

After fitting a 4x4 bonnet to my 2 wheel drive sapph coz, I found that water was getting into the power steering fluid reservior turning it milky. I am presuming that is because it is directly under the bonnet vent. Does anyone know if the 4x4 had a different power steering bottle or cap, or has any body had the same problem. Also need to know the best way to flush out all of the moisture from the system because I have been told that if I don't get rid of every drop of water it will just turn milky again.
Any help on this matter would be greatly appreciated.