What abilities should I max on Zac jungle?

Zac jungle you want to max your W for the increased clear. The only reason to max Q is to increase the amount of damage you can do at range to enemy laners if you're playing him top.

And good job for still trying to jungle Zac! He's one of my favorite champions, but unfortunately his viability in the jungle is under some rather serious scrutiny as he wasn't really in the best place during season 4, and the new jungle has only increased the gap in viability between tank junglers and high sustain/damage junglers. I wish you the best of luck, but be prepared for some rough matches.

Max E so you have potent ganks. I am pretty sure this is how most people play zac anyways.