Oil filters and check valves

[gfl@cc.bellcore.com (grant f lenahan)]

> What does the check valve do?  Assuming they put a basic
> Fram filter on, should I immediately go to the dealer and > get one with the check valve? 
> What would happen if I didn't?

Terrible things.  First, the entire list would laugh
at you.  Then your hydraulic valves would tap
on strat-up for a few seconds.  The worst part
is that this would continue for about 250k miles. :-)

Grant

ps: however, I buy OC-47 (Mann?) filters for $2.75/ea by
the case, so whats the big deal?