</font><font color="blue" class="small">( If I drain and refill with Dexron III will I have any compatibility issues with the remainder of the hyd fluid in the system? )</font>
My experience is that pretty much everything mixes with everything else w/o problems. Personally, I think compatibility issues are phantom creations made by marketing departments, but I'm cynical that way. ATF is super-cheap though, so if you are worried about it, drain the hydro, refill with ATF, then run for a few minutes while exercising everything. Drain and refill again and you'll be all set.
Jay