Below is my BOSCH D3325, and I believe the orange device is the anti-drainback valve (correct me if I'm wrong).
This filter was being used on a 1990's Camry 5SFE 4 cyl. engine. On this engine the filter is mounted in about the 4:30 position pointing down.
Over many past oil changes (using several different brands of filters), I always have an amount of oil that will spill out as soon as the filter is unscrewed from the base. The past two oil changes there has been no oil at all that spills out when it is being removed. Is this simply because the anti-drainback valve is doing an excellent job of what it is designed to do ?
I ask because I never paid much attention if those past filters had anti-drainback valves (and apparently they didn't?). The engine had been off for about 30 minutes, but that is consistent with most of my oil changes. Another variable is that I did take the head off and had it gone through by a shop a year or so ago; and I believe this condition showed up since that time. I want to rule out any valve lapping compound that could have been internal and unseen when I did the installation that could be plugging up the filters although I didn't find the media to be plugged from a visual instpection of the pleats.
Bottom line then is this anti-drainback valve why there was no oil leaking out when this filter was removed? And even though no oil came out, there was plenty of oil that was inside and it did come out (not pictured) just as soon as I cut open the housing so I'm confused.
This filter was being used on a 1990's Camry 5SFE 4 cyl. engine. On this engine the filter is mounted in about the 4:30 position pointing down.
Over many past oil changes (using several different brands of filters), I always have an amount of oil that will spill out as soon as the filter is unscrewed from the base. The past two oil changes there has been no oil at all that spills out when it is being removed. Is this simply because the anti-drainback valve is doing an excellent job of what it is designed to do ?
I ask because I never paid much attention if those past filters had anti-drainback valves (and apparently they didn't?). The engine had been off for about 30 minutes, but that is consistent with most of my oil changes. Another variable is that I did take the head off and had it gone through by a shop a year or so ago; and I believe this condition showed up since that time. I want to rule out any valve lapping compound that could have been internal and unseen when I did the installation that could be plugging up the filters although I didn't find the media to be plugged from a visual instpection of the pleats.
Bottom line then is this anti-drainback valve why there was no oil leaking out when this filter was removed? And even though no oil came out, there was plenty of oil that was inside and it did come out (not pictured) just as soon as I cut open the housing so I'm confused.
