dunno how you feel about this, but....
I have seen the little bubbles go through the loop and eventually go away as they entered my res. Your setup will take longer to bleed but the answer is time imho. You could assemble the loop of components and tip the case over on its side (providing you have a somewhat closed system) and that may help in bleeding the system more. But remember, a leak test should last 24 hours and you should be bled by that time, providing there is not bubbling agents like Dawn or household cleaners in your system