Baxter Performance Oil Filter Anti Drain Adapter???

You are correct! I just got this reply from Kevin Baxter. I am also a little leery of blowing 3 seconds of 140 psi air into my engine to bleed the oil filter down.😳 That is my only hesitation with this product. My compressed air usually has some moisture in it. @mphilleo your thoughts on this?

Baxter reply:
Normally anti-drain back valves work, however, the oil supply galley from the pump to the oil filter and oil supply galley from the oil filter to the engine run parallel inside the engine cover with only a steel plate cover to separate flow, no gasket is utilized. Head space air pressure trapped in the oil filter expands to atmospheric pressure when the engine is shut off. This condition forces the oil out of the oil filter through the center outflow port and empties the outflow supply galley feeding the engine. Air then passes by the steel plate separating the two galleys and allows oil to drain back between the oil filter and back to the pump. By keeping both galleys flooded, no oil flows and air does not enter when the engine is turned off.



Our patent pending check full flow check valve is a precision device and has never failed in our products or testing.



To empty the oil filter prior to filter replacement, apply 3 seconds of compressed air to the Schrader valve.
I can’t make out what he is saying about “galleys” being separated by a plate, and other things. The filter base plate? Can’t make any sense of that. It seems like a lot of talking to confuse. I still have no answer as to why the oil stays put under the check valve, but drains down without a check valve, almost immediately he says. I honestly don’t believe that. Subaru has engineers.
But there is a purchaser here who says he likes it, so there is that first hand real world data. I would go with Subaru, what happened when the car was new on the lot? Clattering on start?
 
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Operative word is theoretical. Blowing compressed air into the engine was the turn off for me. Clear flood mode is always an option or a pre-luber if a person is really concerned with cold starts. Not sure how the system plays into a new car warranty either, the smart money is it gives the car maker an out on a big warranty claim if they notice it or should you make the mistake of not removing it when making a claim.
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I'm not dumb enough to leave my Pedal Commander, Mishimoto catch can, or this device installed if ever the vehicle went in for a warranty claim. I also have the rev hang delete tune in my ECM, which is a game changer with my manual transmission. That will stay. I'll hedge my bets that they don't catch that one. I avoid Stealerships at all costs, except for warranty work. I'm mechanically inclined and do all of my own maintenance.
 
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I can’t make out what he is saying about “galleys” being separated by a plate, and other things. The filter base plate? Can’t make any sense of that. It seems like a lot of talking to confuse. I still have no answer as to why the oil stays put under the check valve, but drains down without a check valve, almost immediately he says. I honestly don’t believe that. Subaru has engineers.
But there is a purchaser here who says he likes it, so there is that first hand real world data. I would go with Subaru, what happened when the car was new on the lot? Clattering on start?
Yeah I didn't comprehend all of what he was saying either. I do notice a very brief little clattering on cold start if the car has sat more than a day. Clear flood is an option but shouldn't have to be done with a filter that has an ADBV that actually works. I'm going to try a Fram Ultra I think before I buy it. Maybe the Boss filter that is on it now will have an ADBV that functions properly?
 
I'm not dumb enough to leave my Pedal Commander, Mishimoto catch can, or this device installed if ever the vehicle went in for a warranty claim. I avoid Stealerships at all costs, except for warranty work. I'm mechanically inclined and do all of my own maintenance.
I never said you were dumb enough, just tossing that out there. Vehicles get towed in for repairs and not everyone remembers to remove mods that can open Pandora's box. I'd consider the unit, but the Schrader valve/air compressor was the deal breaker, for me.
 
I can’t make out what he is saying about “galleys” being separated by a plate, and other things. The filter base plate? Can’t make any sense of that. It seems like a lot of talking to confuse. I still have no answer as to why the oil stays put under the check valve, but drains down without a check valve, almost immediately he says. I honestly don’t believe that. Subaru has engineers.
But there is a purchaser here who says he likes it, so there is that first hand real world data. I would go with Subaru, what happened when the car was new on the lot? Clattering on start?
It's obviously something that some Subarus with the filter mounted base down on top of the engine do, regardless of Subaru engineering. Sounds like they are a candidate for an oil filter with an anit-siphon valve in the center tube, which is basically what the Baxter adapter does.
 
Yeah I didn't comprehend all of what he was saying either. I do notice a very brief little clattering on cold start if the car has sat more than a day. Clear flood is an option but shouldn't have to be done with a filter that has an ADBV that actually works. I'm going to try a Fram Ultra I think before I buy it. Maybe the Boss filter that is on it now will have an ADBV that functions properly?
If an oil filter's ADBV isn't working well then this issue will be worse. But from what I'm understanding, this issue may be there regardless if the oil filter ADBV works perfectly. Let us know what you see when using some different oil filters.
 
Like I posted on the Subie thread......

How I see it. Only in regards to our upside down filters.

The filter media is obviously permeable, will not keep oil on the "dirty" side of it from passing through the filter media to the clean side of the filter when the engine is off. So, the ADBV's job on our upside down filters appears to be to keep only the "dirty oil" on the "dirty side" of the filter media from draining back down into the engine when the oil pump stops pumping. When the engine is shut off, the oil on the clean side will drain to the pan.....therefore creating empty space where some oil on the dirty side will permeate through the filter media and also back into the pan.

Sooo, again, on our upside down filters, if the ADBV is working, oil won't back drain down through the inlet of the filter but some oil will eventually permeate through the filter media and down to the oil pan. So you'll end up with whatever oil on the "dirty side" that did not have the hydraulic pressure to permeate through the filter media still left in the filter.

If the ADBV is not working, you'll have oil from both the clean and dirty sides of the filter draining back into the pan.

Regardless of if the ADBV is working or not, lots of oil will still drain out of it when the car sits.

I'm waiting to hear from Kevin at Baxter, but how I see it.....the adapter places a check valve in the port of the clean oil going to the engine. So NOTHING can drain back into the pan at that point. However, I believe it still relies on a properly functioning ADBV to keep the oil on the dirty side from draining back into the engine. If the ADBV does not do its job, then the oil will just backflow through the filter media from the clean to dirty side and empty out the filter that way. So in order to keep the oil filter completely full of oil when the engine is off, one needs the Baxter adapter AND a fully working ADBV. I may be wrong on this though.
 
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Like I posted on the Subie thread......

How I see it. Only in regards to our upside down filters.

The filter media is obviously permeable, will not keep oil on the "dirty" side of it from passing through the filter media to the clean side of the filter when the engine is off. So, the ADBV's job on our upside down filters appears to be to keep only the "dirty oil" on the "dirty side" of the filter media from draining back down into the engine when the oil pump stops pumping. When the engine is shut off, the oil on the clean side will drain to the pan.....therefore creating empty space where some oil on the dirty side will permeate through the filter media and also back into the pan.

Sooo, again, on our upside down filters, if the ADBV is working, oil won't back drain down through the inlet of the filter but some oil will eventually permeate through the filter media and down to the oil pan. So you'll end up with whatever oil on the "dirty side" that did not have the hydraulic pressure to permeate through the filter media still left in the filter.

If the ADBV is not working, you'll have oil from both the clean and dirty sides of the filter draining back into the pan.

Regardless of if the ADBV is working or not, lots of oil will still drain out of it when the car sits.

I'm waiting to hear from Kevin at Baxter, but how I see it.....the adapter places a check valve in the port of the clean oil going to the engine. So NOTHING can drain back into the pan at that point. However, I believe it still relies on a properly functioning ADBV to keep the oil on the dirty side from draining back into the engine. If the ADBV does not do its job, then the oil will just backflow through the filter media from the clean to dirty side and empty out the filter that way. So in order to keep the oil filter completely full of oil when the engine is off, one needs the Baxter adapter AND a fully working ADBV. I may be wrong on this though.
I did a test a while back on a Purolator PureOne filter to see how well the ADBV worked. It sat full of oil with the base down for a week. I then opened up the ADBV by sticking bent Q-Tips into 3 of the base holes and captured all the oil that drained out of the filter. The oil did not migrate through the media and out the center tube. There is enough surface tension and lack of atmospheric pressure on the dirty side of the media to push the oil through the media.


Also, on my Toyota Tacoma, the oil filter is on top of the engine and is mounted vertical with base down. The filter never drains itself out through the center tube even if it sits a week. I have to punch a hole in the top of the oil filter when I do an oil change to make the filter drain - that's an old trick I learned when I owned RX-7s. It acts the same way as the filter the filter I tested. It needed atmospheric pressure inside the dirty side to make the oil drain out through the media and center tube.

The Baxter Subaru filter adaptor essentially just adds a check valve in the center tube to prevent the filter draining out through the center tube. Just like some oil filters actually come with a built in "anti-siphon" valve built into the filter's center tube. If Subarus drain the oil out of the oil filter when the filter ADBV works 100%, then somehow atmoshperic pressure must get inside the filter to start that draining process.
 
I did a test a while back on a Purolator PureOne filter to see how well the ADBV worked. It sat full of oil with the base down for a week. I then opened up the ADBV by sticking bent Q-Tips into 3 of the base holes and captured all the oil that drained out of the filter. The oil did not migrate through the media and out the center tube. There is enough surface tension and lack of atmospheric pressure on the dirty side of the media to push the oil through the media.


Also, on my Toyota Tacoma, the oil filter is on top of the engine and is mounted vertical with base down. The filter never drains itself out through the center tube even if it sits a week. I have to punch a hole in the top of the oil filter when I do an oil change to make the filter drain - that's an old trick I learned when I owned RX-7s. It acts the same way as the filter the filter I tested. It needed atmospheric pressure inside the dirty side to make the oil drain out through the media and center tube.

The Baxter Subaru filter adaptor essentially just adds a check valve in the center tube to prevent the filter draining out through the center tube. Just like some oil filters actually come with a built in "anti-siphon" valve built into the filter's center tube. If Subarus drain the oil out of the oil filter when the filter ADBV works 100%, then somehow atmoshperic pressure must get inside the filter to start that draining process.

I just got off the phone with Kevin at Baxter. He explained everything. Lots more going on than just at the filter. He replied via the OP in fewer words via an email vs what he told me on the phone, but the jest of it is quoted below. He said he will send me over a couple pictures of the galleries he's referring to. What you saw is explained below too.

I think I'll be ordering one. One MUST evacuate the filter before changing it though, if not, you will have a mess, as the filter and both oil galleries will be flooded with oil and you will have oil running everywhere if you don't evacuate the filter before spinning it off. It's not only the lack of oil in the filter, but also in the return and supply oil galleries.

This is what the real issue appears to be:
Baxter reply:
Normally anti-drain back valves work, however, the oil supply galley from the pump to the oil filter and oil supply galley from the oil filter to the engine run parallel inside the engine cover with only a steel plate cover to separate flow, no gasket is utilized. Head space air pressure trapped in the oil filter expands to atmospheric pressure when the engine is shut off. This condition forces the oil out of the oil filter through the center outflow port and empties the outflow supply galley feeding the engine. Air then passes by the steel plate separating the two galleys and allows oil to drain back between the oil filter and back to the pump. By keeping both galleys flooded, no oil flows and air does not enter when the engine is turned off.
 
I just got off the phone with Kevin at Baxter. He explained everything. Lots more going on than just at the filter. He replied via the OP in fewer words via an email vs what he told me on the phone, but the jest of it is quoted below. He said he will send me over a couple pictures of the galleries he's referring to. What you saw is explained below too.

I think I'll be ordering one. One MUST evacuate the filter before changing it though, if not, you will have a mess, as the filter and both oil galleries will be flooded with oil and you will have oil running everywhere if you don't evacuate the filter before spinning it off. It's not only the lack of oil in the filter, but also in the return and supply oil galleries.

This is what the real issue appears to be:
Yeah I think I'll pull the trigger on it sooner than later. I keep flip flopping back and forth on this but I just need to do it!😎
 
I just got off the phone with Kevin at Baxter. He explained everything. Lots more going on than just at the filter. He replied via the OP in fewer words via an email vs what he told me on the phone, but the jest of it is quoted below. He said he will send me over a couple pictures of the galleries he's referring to. What you saw is explained below too.

I think I'll be ordering one. One MUST evacuate the filter before changing it though, if not, you will have a mess, as the filter and both oil galleries will be flooded with oil and you will have oil running everywhere if you don't evacuate the filter before spinning it off. It's not only the lack of oil in the filter, but also in the return and supply oil galleries.

This is what the real issue appears to be:
I was also a little hesitant using compressed air to drain the filter down in the event that impurities (sediment and or water) from the air line are introduced in the oil but doesn't the air get filtered by the filter or no? I'm going to ask Kevin.
 
I was also a little hesitant using compressed air to drain the filter down in the event that impurities (sediment and or water) from the air line are introduced in the oil but doesn't the air get filtered by the filter or no? I'm going to ask Kevin.

I have an air/water separator on my compressor, which has somewhat of a filter. I'm not too concerned about that.

I think you may be onto something though. It's got to be filtered. It's pushing the oil from the dirty side through the media to the clean side out to the engine. I don't think it would push it from the clean side to the dirty side......that would push any trapped contaminants back towards the oil pump.

Maybe ask him that too......
 
I actually just ordered one about 15 minutes ago. :)
I'm not far behind. 👍 FYI the Purolator Boss PBL22500 will work with the Baxter and has a 22psi bypass, but I know you're not to worried about that! 😂 Also FWIW, the Amsoil EaO17 is compatible and has a 18-24 psi bypass.
 
I have an air/water separator on my compressor, which has somewhat of a filter. I'm not too concerned about that.

I think you may be onto something though. It's got to be filtered. It's pushing the oil from the dirty side through the media to the clean side out to the engine. I don't think it would push it from the clean side to the dirty side......that would push any trapped contaminants back towards the oil pump.

Maybe ask him that too......
I just sent him an email regarding these concerns. I'll post the reply.👍
 
I think I'll be ordering one. One MUST evacuate the filter before changing it though, if not, you will have a mess, as the filter and both oil galleries will be flooded with oil and you will have oil running everywhere if you don't evacuate the filter before spinning it off. It's not only the lack of oil in the filter, but also in the return and supply oil galleries.
Sounds like there is something unique about the Subaru oiling system that allows it to drain the oil filter from the center tube - it sounds like it need a filter with an anti-siphon valve in the filter, which is what Baxter is providing in his adaptor. I know my Tacoma doesn't drain the filter, and it's mounted vertical with the base down. I need to punch a hole in the dome of the filter to make it drain out the center tube.
 
I was also a little hesitant using compressed air to drain the filter down in the event that impurities (sediment and or water) from the air line are introduced in the oil but doesn't the air get filtered by the filter or no? I'm going to ask Kevin.
I have an air/water separator on my compressor, which has somewhat of a filter. I'm not too concerned about that.

I think you may be onto something though. It's got to be filtered. It's pushing the oil from the dirty side through the media to the clean side out to the engine. I don't think it would push it from the clean side to the dirty side......that would push any trapped contaminants back towards the oil pump.
My bet is you would only need 10-15 PSI to remove the oil out of the filter - just keep the air pressure on the filter for a bit longer to get the oil through the media and out the center tube. IMO, you don't want to hit it with a lot of air pressure because too much might open the filter bypass valve.

When the filter is pressurized with some air, the ADBV should seal even better against the base plate, and all the oil should go through the media (getting filtered) and out the center tube to the drain back to the sump.
 
My bet is you would only need 10-15 PSI to remove the oil out of the filter - just keep the air pressure on the filter for a bit longer to get the oil through the media and out the center tube. IMO, you don't want to hit it with a lot of air pressure because too much might open the filter bypass valve.

When the filter is pressurized with some air, the ADBV should seal even better against the base plate, and all the oil should go through the media (getting filtered) and out the center tube to the drain back to the sump.
Baxter suggests 30 psi
 
Baxter suggests 30 psi
Ask him why so high. I highly doubt it takes that much air pressure to move the oil out of the filter through the media and past the check valve in the adapter. Ask him at what pressure does the check valve in the adapter open up at ... it shouldn't be much, like 2-3 PSI if he designed it right.
 
Ask him why so high. I highly doubt it takes that much air pressure to move the oil out of the filter through the media and past the check valve in the adapter. Ask him at what pressure does the check valve in the adapter open up at ... it shouldn't be much, like 2-3 PSI if he designed it right.

2 psi is what he told me on the check valve.

He said that he has had people connect a bike pump to it to evacuate it who don't have air compressors. So I'm guessing you could do it with lower pressure but it just may take longer.....like you said.
 
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