The Vanagon oil filter does have a one way valve and a bypass. The
diaphragm type thing at the top prevents oil from flowing backwards. My
response is based on the oil draining is not the issue or problem. Do
lifters clatter after each oil change? It takes 15-30 seconds for oil
pressure to develop afterwards. The clatter problem is really in the
lifters and I have seen it on the I4 and Audi engines also.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
Of jimt
Sent: Monday, May 02, 2005 11:40 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Anti-Drain Back Valve in Oil Filters??

Especially since that valve is a bypass valve not a holding valve.  Note
its
position.  If the media becomes clogged the oil then pushes against the
valve with enough pressure to go around the media and back to the
engine.
The only anti drain associated with a filter I have ever seen is one way
valves in external lines.  Also note the orientation of the filter and
where
it is in the line of the engines oil system.
jimt

On 5/2/05 4:25, "Dennis Haynes" <dhaynes@OPTONLINE.NET> wrote:

> Non-sense and wives tales!
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
Behalf
> Of tabe johnson
> Sent: Monday, May 02, 2005 12:47 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Anti-Drain Back Valve in Oil Filters??
>
> OK --- can someone please explain how and why
> the anti drain back valves in the Mahle and Mann
> filters work so much better at keeping lifters
> from clacking?
>
>

........................................
jimt
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Remember that sanity is optional.
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