I've never needed to run a dub with an external oil circuit before,so this may seem an obvious question.I'll be fitting an oil cooler via a thermostat.The majority of my driving is work and back 6mile runs so the cooler will rarely come into play.When it does(thermostat opens),i'll initailly see a drop in oil level as the external circuit fills so do i manually prime it first?.
Also,because i'll mostly have this "dead leg" of oil doing nothing most of the time,when it's time to do an oil change is it preferable to drain this part of the circuit down seperately,then re-prime,or do i just get it stinking hot,let it do it's thing then refill to level?

I've a feeling i'm over complicating things here...

Ade.