josh and ben

Hi all I have a 07 2.0 tdci galaxy In the recent cold weather the steering has begun sticking when trying to turn right normally clears within a mile and is fine from then on until next morning. Has anyone else come across this? Ford and the dealer seem to be denying any knowledge of fault with "no fault found" being the reply. Needless to say warranty expired 2 months ago. Thinking about changing the pas fluid just as matter of coarse really, anyone changed pas fluid on a mk3 galaxy before? is there anything special to be done regarding electric pump/bleeding system? Thanks