I've got a question for runners...?

6 months ago I ruptured my achilles (partial rupture) and have layed off running for a while. Now I feel no pain, but there is a definite difference in the size. Will it go down? My doctor doesn't speak English well (I live in Germany) and I don't speak Deutsch well, so he didn't explain much. I want to start training for another marathon, but am a little aprehensive, worried it will re-injure. Whose had this problem before? If I feel no pain, should I just JUMP right back into running? I need to get back in gear!