The Oros were DOT brakes and the DOT fluid absorb humidity. So, if you did not use your bike for a long time and parked it in moist atmosphere there is a significant probability you will have to purge them.
OK I just saw the 30 posts before being able to send a PM rule. I don't know if you can send me one. Will have a look at the forum but I don't really want to spam randomly some topics so let me know when you see my messages.