Th400 not going into third

[Big70]

So I had a thread on here talking about not being able to shift into third with my th400. Some one said it could be my modulator. One thing I do know is I only have a vacuum hose connected all the way up to my intake mana fold. no hard line. My question is can I just make a hard line out of brake line and vacuum line at both ends? Also some one asked if I over filled it and I think it might be a half quart to a hole quart over. This tranny sat for almost ten years but ran fine when we pulled every thing. please help. Thanks in advance!