The Mann inline 4, 719/5, and Vanagon, 719/12, filters both have
antidrainback flaps inside the perimeter oil entry holes.  The Vanagon
bypass valve opens at 1 bar the inline 4 valve opens at 2.5 bar.

-Dana-

Jay L Snyder wrote:
>
> The "red stuff" is probably Marvel Mystery Oil or  ATF.  I think the
> correct viscosity oil is as, or maybe more important than the filter.  Too
> thick and the lifters won't get sufficient oil, too thin and they will
> bleed down.  Most of us tend to use oil on the thicker side as the engines
> age.  The Vanagon filter will only partially drain, if at all, on
> shut-down.  There is some internal differences as to pressure drop across
> the filter medium.  Stick with Mann or Mahle and pre-fill on changes--it
> can't hurt.  There isn't that much difference in cost.
>
>                                                         Jay '85 Westy