Hydroboost/power steering fluid question

[Cobradavid]

I need to top off the fluid in my power steering reservoir. I'm using the donor (2001 GT) PS pump, PS rack, and hydroboost brake booster. The shop manual says to use Mercon fluid, but just plain Mercon isn't made anymore. Ford TSB says Mercon V can be used in the transmissions that used to use Mercon.

I've search the interwebs and haven't found good answers to my question:
* Can I use Mercon V in the power steering (and hydroboost) system which originally called for "just plain" Mercon?
* Should I drain the system of the old Mercon and re-fill with all Mercon V, or is it ok to have a mix of Mercon & Mercon V?

Looking for opinions.

Opinions backed up with data would be even better :D

Thanks in advance.

David

[Joecobr]

It has been some time since I filled mine. I had the same question. If I recall correctly the labeling on the Mercon V stated it replaced the plain Mercon for older vehicles.