Purging Oil System on 912S
"If an optional oil thermostat is installed it will by pass the oil cooler when cold; and feed the oil cooler when warm. Extra attention should be given to assure this circuit is properly purged of air."
So, how do I properly purge the oil cooler of air. How is this supposed to be done? The video is silent regarding this matter, except to say that it should be done.
Thanks!