Funny you should say that. I had three Tocco levers and all of them started to leak in different places after having ridden only a couple of times. I always sent them back to my dealer and after a short while he took them out of his catalogue because I wasn't the only one doing so.
I currently run Racing Line levers (the ones with the double seal pistons) and other than a tiny leak on the bleed bolt* on one of them, they work just fine.
*Some ptfe tape helped on that.