brake light went on

[pcbootleger]

so I got off work and into my car and noticed my brake light went on. I pressed the pedal and it was as if there was no response in the brake pedal at all. Luckily I work the night shift and go home at 3:30 am when there is no traffic so it wasnt too big of a problem driving home. But what would cause this problem? Would it be the master cylinder? I just want to know what it most likely is so I dont waste my time fixing something else for nothing.l oh and by the way I own a 84 300zx n/a just like in my sig if that matters.

[NISTECH]

sounds like you got no fluid in your resivor. first check your brakes at all wheels,make sure you arent losing fluid through the calipers. then check your master cyl where it bolts to the brake booster see if fluid has been running out from behind it. where ever you find the leak thats what you need to fix. then have someone help you bleed the system of air.