You're changing the discussion and going in the weeds. Show me where I "blindly" claimed all ADBVs work 100% of the time. Most of them do, some don't ... but overall they work. If they didn't, they wouldn't even be on oil filters.You can NOT seriously, after all this time - - -
*blindly* believe that the ADBV:
1) always works,
2) all the time , & in
3) 100% of all filters made - that are equipped with such a feature?
Don't be so naïve - - - - -
Auto engineers are not - - that is why it isn't "depended upon" for any critical function.
AT MOST - - it is a luxury - - and NOTHING more.
If it works / functions 100% - then yay, happy days.
How often do they operate 100% of the time?
Well - - I'll never put any real money on it.
It seems like you don't really understand the purpose of the ADBV, and that you believe it's only to keep oil in only the oil filter (post #15 - "At BEST - - the valve is there to keep the filter from draining dry....") - wrong. Seems the ABDV is as misunderstood as PD oil pumps and oiling systems.