Are you talking about the plastic valve you see at the far end of the filter can when you look into it? That's not an anti-drain back valve, that's a filter media bypass valve. It's supposed to open and let the oil circulate around the media, instead of going through it, when either the oil is too thick to flow through, or the filter media is too obstructed.
The anti-drain valve is the metal ring or coil spring you see around the base of the threads. If you or anyone else wishes to learn all sorts of stuff about oil filters, go to a parts store and request to see the AC/Delco filter book. This book contains all sorts of information about the various valves in filters, the media, construction specifications and such. It's #1 for figuring out which various alternative filters will fit your particular vehicle. >>> "Steve R." <[EMAIL PROTECTED]> 01/15/03 01:57AM >>> My 2 cents on the article I have seen this article years ago and since then I always check to see the rubber valve on the filter. I don't remember if it stated it, but for an example: Look at a Fram filter and the Fram Tough Guard filter. The Tough Guard has a 'anti drain back valve", so when you shut the car back off, the oil that might be in the process of being clean does not drain back into the pan.....well that's what I like to think..but it allows the filter to retain oil when your vehicle is turned off so your engine benefits from a filter full of oil at startup. I buy a couple of brands and that is what I look in a filter, because it does make sense. Ya you can talk about a filter being cheap etc., but you should consider this in the construction of the filter. I do buy Purolator filters because of the gasket and I think Allied Corporation as the store brand soda at the local supermarket. :) /// [EMAIL PROTECTED] mailing list /// Send admin requests to [EMAIL PROTECTED] /// or try http://www.team.net/cgi-bin/majorcool /// Archives at http://www.team.net/archive /// Send list postings to [EMAIL PROTECTED] /// Edit your replies! If they include this trailer, they will NOT be sent.
