Here's what I found on the Hayden website. Seems to work as designed:VStar650CL wrote: ↑Tue Aug 01, 2023 5:06 pmThen Hayden must be using something in there besides a traditional H-Valve design, but if that's the case, I stand corrected. I'll have to check that out. I wouldn't sweat the bubbles if they're diminishing, just if you still have them after driving awhile. It may be that your cooler is connected with pressure on the top, that makes it harder for the pump to flush out trapped air because it's fighting the buoyancy of the bubbles. That's the main reason for all that bottom-up designing Nissan does.
https://www.haydenauto.com/en/products/ ... ss-coolers