1st get it clean then dry.top up fluid at master cylender.then gently squeeze lever to find where the leak is comming from.either,master cyl at lever.flexible pipe from master and all connecting joints ,or caliper itself.be aware that a tiny chsff in the rubber line can be enough to leak.over time it will lose all fluid from a tiny hole.not an expensive job for an indipendant unless it mstr or calpr..
caine
July 2008