I have an odd problem with the flow of the air conditioner.  I had to have
the front brake lines replaced because of corrosion, 77500K, in fact one
actually perforated.  Right after that the problem with the air flow began,
maybe just a coincidence.
   The air flows from the panel just fine until I begin to accelerate, then
the air is slowly deflected to the defroster and stays that way until I let
off the gas.  At that point flow returns to the panel.   I can hear the
doors changing.  I checked the
vacuum line from the vacuum booster to the junction at the intake manifold
and found nothing loose and no evidence of rodent activity.  I see nothing
up under the dash board that looks loose or chewed.  What are some
possibilities?  I guess it goes to the shop soon.