4 wheel drive not engaging after keeping in 4Runner in storage

I have a 95 4 Runner. I had it stored at a friends house for several months. He did use it some when he was down a car for awhile but i trust him with my life. When I parked it the 4 wheel drive was working fine. I finally picked it up last week and i can't get the 4 wheel drive to engage. Iv driven it around some, checked it on a steep off road grade to make sure it wasnt just the light out. i crawled under it and had a buddy work the selector and best i can see its all working properly. Does anyone have any ideas what may be going on?

 

Keep messing with it until you get it to engage, patience grass hopper.

 

Im guessing vacuum leak or something wrong with the ADD. Does the 4wd light work?

 

Thanks John I'll keep trying but i have messed with it quite a bit. Welcome home brother. Vietnam vet 1970 USMC

 

Thanks. Whats the ADD? and no the light does not work.

 

http://www.4x4wire.com/toyota/tech/add/