98 Breeze Weird Noise/Oil

My 98 Plymouth Breeze started making a grinding noise towards the back drivers' side when the brakes are applied, even tho there is no difference to the way the brakes are functioning. Thinking the brakes needed to be looked at, I sent my BF to work on it, reminding him to check the oil on his way. The car seems to go thru alot of oil... When he put in about 1.5 quarts of oil, the grinding noise stopped!?! Any clues what this might be?? Thanks for any help/advice. AND NOW HE JUST CALLED AND TOLD ME THAT THE EMERGENCY BRAKE LIGHT HAS COME ON??!!!

Well, the grinding noise may have been because the oil was low.
The brake light coming on usually means the master cylinder is gone (Brake Master Cylinder).