ANTI-DRAINBACK VALVES
- Thread starter Pete C.
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Filter mounted base down?
I don't worry too much about the ADBV. My WRX has the filter mounted base up. Some have claimed that the primary value of this little piece of rubber is to protect against backflow spitting stuff back to the oil pump.
I don't worry too much about the ADBV. My WRX has the filter mounted base up. Some have claimed that the primary value of this little piece of rubber is to protect against backflow spitting stuff back to the oil pump.
I go along with Tkeith. With a bypass stuck open, the oil could run out when you remove the filter unless it was a hole up design. I recently discussed this in a post to another thread. I will forgive anybody who missed in in all the other garbage in that thread.
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I think the main reason for an ADBV is to prevent backwash of debris. It doesn't have to be perfect to accomplish this goal. This may just be a cofunction of it.
Filters are, and have been, mounted in various manners in various applications over time. Some empty ..some don't. Virtually all have ADBV.
Filters are, and have been, mounted in various manners in various applications over time. Some empty ..some don't. Virtually all have ADBV.
Does removing the drain plug and oil filler cap to let the oil out and let air in, before removing the filter, have anything to do with your question Pete......
Triple_Se7en
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Most GM vertical AC filters are not equipped with an ADBV. My AC Delco PF-59 is one example.
There must be a path for air to enter a full filter for any oil to drain out. As long as there is an unsealed outlet hole, it’s certainly possible for air to get into the filter and for oil to get out. How much air gets in (and how much oil gets out) will depend on the locations of the engine’s oil passages and bearings after the oil filter. For example, if the oil passage after the filter outlet hole heads downward to the first plain bearing, gravity will take over and at least some, if not most, of the oil will eventually “leak” out, even with a perfect ADBV over the inlet holes. If the oil passage after the filter rises to a point above the highest point of the filter before reaching the first plain bearing, no oil would “leak” out of a filter with a perfect ADBV.
Yes, if you poke a hole in it before removing it from the filter mount.quote:
Originally posted by Pete C.:
Hey guys, can a filter (any brand/manufacturer) have a PROPERLY working ADV and still be empty when you take it off the engine/mount?
Before Ya'll jump all over this, put on your thinking caps and think about it.
777,
I think you meant to say that the GM filters don't have bypasses, rather than not having adbvs. GM engines have the bypass in the filter mount so the filter doesn't have one internally. Most all filters do have an adbv though.
The old Chevy LUV uses a filter that has a bypass , but that truck was just a rebadged Isuzu truck.
I think you meant to say that the GM filters don't have bypasses, rather than not having adbvs. GM engines have the bypass in the filter mount so the filter doesn't have one internally. Most all filters do have an adbv though.
The old Chevy LUV uses a filter that has a bypass , but that truck was just a rebadged Isuzu truck.
I used to use an AC PF52 for a Lumina APV. The owner's manual said either a PF52 or PF51 were fine. I saw a PF51 once, and the only difference seemed to be the lack of an ADBV. The filter was mounted baseplate up at about a 45° angle.
I forgot to add in my post above that in those cases where the oil can drain out of a filter with a properly working ADBV, the amount that can drain out is dependent on the orientation of the filter. Open end up, no oil can drain out. Open end down, all the oil can drain out, etc.
I'm somewhat curious as to how various cartridge filter assemblies handle anti-drainback/anti-backpressure.
I played around a little with the one on my Ecotec. The element has a part sticking down with an O-ring. When you remove the cap, the element comes with it allowing more oil to run out leaving the element empty and cleaner to remove. With the element out, oil will run down to the crankcase. In place, and you can fill it with oil. There must be an ADBV somewhere, defeated when you remove the element. You could prefill that way. I don't because I think it is more important to clip the element to the cap correctly than any benefits of prefilling. I am sure the bypass is much like other in the block GM product.
It seems possible. If you have the threaded side mounted down on an engine, the oil could slowly leak through the media through the oil passages.
However, the filter would have to be mounted above the the oil galley and the main bearings.
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