How to drain old oil from filter with ADBV ?

[Gary Allan]

Quote:
From what I've gathered, when the media is soaked with oil, that coupled with the ADBV will create a small vacuum on the dirt side of the filter.


The center tube lets air in the full height of the media. The oil should be able to freely flow out of the open end of the filter. There should be no vacuum or anything to prevent the oil from seeking an outlet through the lower/open end media into the center well.

That's the basis of my speculation that the open end of the media saturates first. There should be nothing to prevent the filter from (nearly 100%) emptying when inverted. It doesn't ..hence my suggested cause.

 

[Drew99GT]

Gary, then why does no oil flow out unless you poke the ADBV open?

I've used to set filters upside down in a funnel to get them to drain overnight, and many times they won't, unless you poke the ADBV open. I'd call that a vacuum.

When I hold a used filter upright and poke the valve open, you can see oil immediately fill the center tube.

 

[Gary Allan]

Because the upper (down facing when inverted) strata of the media is virtually plugged due to it seeing the lion's share of the flo early on in the filters use.

 

[Sayjac]

Originally Posted By: Drew99GT

As to trying to drain and reuse a filter, why bother? The amount of oil in the filter is a drop in the bucket compared to what's left in all the oil galleys and on top of the cylinder head/heads. Either replace it or just leave it on.
+2

That said, I own an 07 Accord still under warantee. Because it is, I have let the dealer change the oil. As long as I can keep it in the $20-25 range, I can live with that. My point though is that the dealer changes out the filter every time. If that practice didn't meet warantee standards they wouldn't do it.

When I start changing the oil myself, I have to drive it up on ramps to change it, I will change the filter. There may however, come a day when I leave the filter on every other change, just not now.

Lastly, I'm not an expert nor do I play one on TV, but I find the idea of a better UOA by leaving the filter on, counterintuitive. But, that's just me.

 

[TallPaul]

Originally Posted By: HTSS_TR
Just poke a hole to the ADBV and drain the oil ?
To drain a filter I am throwing away, I just put a screw into one ADBV hole and it drains nicely.

 

[Gary Allan]

Quote:
When I hold a used filter upright and poke the valve open, you can see oil immediately fill the center tube.


This I have a hard time reasoning. I've never seen the center tube fill quickly. When prefilling, it's a slow process.


..but I suppose between the saturated media and being oil soaked that there would be some point where you would reach a vacuum status. To test this, I would leave the filter inverted and tap a hole in the closed end. If the filter completely drained ..then there was indeed a vacuum preventing drainage. If it's still containing oil...

When you open the ADBV, you're providing an easier path for air ..but not the only one.

Also keep in mind that there will be cached oil in the base that will never make the center well with the open end up.

 

[PandaBear]

Originally Posted By: HTSS_TR
Leave filter untouched would leave up to 1/2 quarts old oil in filter and filter mount.


That's exactly the point of the ADBV. Old oil in the filter is better than no oil in the filter. Even if you are doing oil change it is better for the engine to have oil that it can use right away. That small amount is not going to hurt anything when it gets diluted with the new oil in the long run.

Heck, if this bother you, change your oil 5% sooner (i.e. 500 miles earlier). It will have the same effect, since oil gets dirty gradually instead of suddenly at a particular mile.

Keep in mind that your typical dino can last 7.5k in the best case and most can easily last 5k, so why are you worrying about a little more old oil you couldn't reach in the engine?

 

[TallPaul]

PandaBear makes an excellent point. Just change the oil 500 miles sooner and call it a day. Your engine will never know the difference.

 

[Jim 5]

Originally Posted By: sayjac
Lastly, I'm not an expert nor do I play one on TV, but I find the idea of a better UOA by leaving the filter on, counterintuitive. But, that's just me.

That is because you do not yet understand the principle of filter media loading. Spend some time in this section reading and you will.

 

[Sayjac]

Originally Posted By: Jim 5
Originally Posted By: sayjac
Lastly, I'm not an expert nor do I play one on TV, but I find the idea of a better UOA by leaving the filter on, counterintuitive. But, that's just me.

That is because you do not yet understand the principle of filter media loading. Spend some time in this section reading and you will.

Apparently every Honda dealer I've dealt with either doesn't understand, or doesn't care about that principle. Under warantee or otherwise, they replace the filter each and every time. Conclusion, leaving the filter on a Honda is only a minimum recommendation not a requirement.

Honda also has a 7500-10000 mile OCI on dino, except under severe service. I personally would not push it that far. But, that is my comfort level and choice. Just as it is a choice whether to change the filter each time. Besides Honda, what other auto manufacturer recommends changing the filter every other change?

Lastly, while I may be a relative newbie to this forum, I have read this board and others on the forum for several years. Add to that some 40 years of changing my own oil on many different vehicles, I would hardly call myself inexperienced. Thanks though for the friendly advice regarding this lowly newbie's reading habits on this forum.

 

[Jim 5]

Originally Posted By: sayjac
Originally Posted By: Jim 5
Originally Posted By: sayjac
Lastly, I'm not an expert nor do I play one on TV, but I find the idea of a better UOA by leaving the filter on, counterintuitive. But, that's just me.

That is because you do not yet understand the principle of filter media loading. Spend some time in this section reading and you will.

Apparently every Honda dealer I've dealt with either doesn't understand, or doesn't care about that principle. Under warantee or otherwise, they replace the filter each and every time. Conclusion, leaving the filter on a Honda is only a minimum recommendation not a requirement.

.

Most people on this board obsess over what will deliver the best used oil analysis. The most eductated among us, namely Terry Dyson (not me) says that leaving the filter on for 2 OCI's (in hondas that recommend it in the owner's manual) does deliver the best used oil analysis. Not to mention a marginal cost savings.

I'd never say it was a bad thing to change the filter every time - its a prudent and sensible practice. But to be fair, it would be incorrect to say that it is always the better practice. Hard data and manufacturers' recommendations support leaving the filter on for 2 OCIs in these vehicles.

On the other hand, dealerships can not afford to care about used oil analysis. They care about expediency and eliminating risk/liability. That being the case, what the dealerships do makes sense. They can't risk leaving that filter on for 3 or more OCIs by mistake. It would after all be very hard for them to keep track of whether the filter was due to be changed or kept on with respect to every random car that comes in.

My comments were not meant to be condescending though unfortutely they have been taken that way.

 

[Audi Junkie]

Some filters are the size of a football and I definately drain them. Not every drop, but wth not?