leaky brake reservoir?
 

i have a ls1 style master cylinder and reservoir on my car, i've noticed that there is brake fluid on top of the reservoir after i drive the car. The cap is in good shape, so is the seal. It almost seems to be squirting out, sometimes there is some on the underside of the hood?

could a bad master push fluid out the cap?

is it overfilled? if to high, after driving for a while brake fluid expands due to heat.
clean off brake fluid and have someone stand on the brakes while you visually lok to see where its coming from. if you need a master i have one on the shelf cheap(o.e. gm part) pm me if needed