Check valve in AC vacuum line: Why? (1.6n/a)

[ldeikis]

I'm the newish owner of a 81 rabbit with a n/a 1.6.  The check valve in the vacuum line to the gizmo that switches the AC/heat ducting jammed up on me.  I've been driving around looking for a check valve that small at various autoparts stores without much success...  I've been wondering, though--why does it need a check valve there?  Is it just to isolate a potential vacuum leak in that circuit from affecting the brake booster?  Can I leave it off until/if I find the right size with no ill affect?  Indefinitely?

Thanks,

Luke

[somolovitch3]

By "jammed up" do you mean it failed in the open state or the closed state?

Yes you need one in there. When there is no vac for the booster to play with, you no stop!

IIRC Ford had a little one fitted to the decel vavle on the throttle, 1970's?

Any one will work, you might have to play around with adaptors and hose sizes a bit.