how come my brake lite comes on on a 1991 chevy s10 and no loss of fluid

ok this easy if your pedal brake was bad you will most likely get an ABS light now about your "Brake" light im assuming its showing in you in ur instrument panel.... that "brake" light is for your parking brake it means something is wrong with you parking brake.. easy check engage your parking brake put your car in gear and if you car moves your parking brake pads are bad and need to b replace or if your parking brake pads are good then your parking brake just needs to b adjusted if u engage ur parking brake and cant disengage it or cant engage it at all it needs to b look at too but long story short im positive its your parking brake

front breaks may need changing,rear may need adjusting.

Possible that the rear drum brakes need to be done, cleaned and adjusted. We suggest that to keep your brakes healthy that you clean and adjust the rear brake shoes and drums yearly. If you check all the brake componets and everything looks good master cylinder will be no good.

OK IF YOU HAVE A BRAKE LIGHT AND NO ABS LIGHT WITH A SPONGY PEDAL AND ALL THE BRAKE PADS AND SHOES ARE GOOD , ITS A SIMPLE MATTER OF AIR IN THE BRAKE LINES WHICH HAS FORCED THE PROPORTIONING VALVE OUT OF PLACE TURNING ON THE LIGHT . JUST SIMPLE BLLED THE BRAKE STARTING FRONT THE LEFT REAR THEN RIGHT REAR THEN LEFT RIGHT AND FINNALLY LEFT FRONT MAKEING SURE THAT A SOLID FLUID STREAM IS COMING OUT OF BLEEDER VALVE . IF YOU DO NOT KNOW HOW 2 DO THIS AND HAVE SOME ONE TO HELP TAKE IT TO A LOCAL SHOP . MESSING UP COULD MEAN NO BRAKE AT ALL.