Usually they only leak because the crud in the old fluid gets in-between the seal and the piston. I've saved many Masters by simply flushing and bleeding them with new fluid. No issues or leaks after doing so either.

 

This could be your problem. I know there was a thread I saw a week or two ago explaining why these clutches are junk for the S2000 along with members posting about failures and recommending to people to stay away from them.

https://www.s2ki.com/s2000/topic/110...nny-fail-help/

 

My CMC leaks and has been leaking since I got my S almost 3 years ago. I top off the fluid and I'm good to go so I'll have to agree with the others that you CMC is more than likely not the issue.

Edit: didn't mean to double post, but look through that thread. OP was having similar issues as well an an Exedy clutch.

 

It's not so much the clutch itself as it is the bearings. They'll work fine for a push type clutch but ours is pull type, and the stress that gets put on the races while pulling it is what leads to their early demise. That's why you pay so much for the release bearing from Honda, yes some of it is brand mark up, but it's a very very high quality unit.

Also thanks for the explanation Jordan, I always wondered why they leaked with old nasty fluid but hardly at all with fresh fluid.