I too am having this problem. I am on Windows 7.
Both my copies of Photoshop CC and Photoshop CC 2014 show ACR version 8.0.0.137. My copy of Lightroom shows ACR vers 8.5. This afternoon I reinstalled Photoshop CC using the "previous version" directions listed in the above post dated June 23 - no effect on updating CC or CC 2014 to ACR 8.5.
When I open the "Help" "Updates" menu in Photoshop CC 2014, it shows that my system is current and updated (which it obviously is not). Preferences there also list Photoshop Camera Raw 7 and Photoshop Camera Raw 8, so update preferences seem to be set correctly, yet it is not picking up the need to update to version 8.5.
I'm at a loss as to how to proceed. Any additional help is appreciated.