Master cyclender question.

Ok its been a wile but I have to ask the, rear of my master is almost empty,me has a leak some were.So is the rear for the front brakes or the rear brakes,i kind of wonder why the brakes did not seam right.i have manual 4 drum brakes,as of now i see no drips but under were the master bolts to the fire wall the paint look not right but dry.I will fill it up tomorrow and see if it leaks there,but for now need to know my first question.PS all wheel cyl and lines are like 2 years old but who can say how long **** last now a days we do live in a throw away world. now.