Ford Repair: Ford C-4 Transmission, vacuum lines, vacuum line

Question
I have a '65 Mustang with a C-4 tranny which worked fine for many years but this year when I took it out of storage it would not move in drive or low.  Reverse was fine.  If I let the engine warm up for two or three minutes all is fine.  Once it goes it works fine all day.  When I first start it I can put it in D or L at about a 1000 PRM and it will go after about 40 seconds.  Low works best for this.  Like I said, once it goes it works fine.  Please advise!
Tom

Answer
TOM

the first thing to do is check the fluid level.start car up and let warm up. then check the fluid level.the other thing to check is the vacuum lines going to tranny.i would also check the vacuum modulater.when you follow the vacuum line to tranny there will be a rubber line that goes to modulator,make sure its connected and not cracked.if after you try these things and it doesnt work let me know. hope this helps.

ken