Something wrong with my 06 Kia Optima's brakes?

[Ribbons]

I've had this car since October and it has around 48,000 miles on it. I've had no problems with it, and had an oil change about a month ago with a 27 point inspection, all checked out. Everything was fine until today when I started to go out. I put the brakes on lightly and the force felt like I'd been hit from behind. I kept testing it, and there's a terrible graunching noise and the brakes went on so hard it felt, again, like I'd been hit from behind. What could it possibly be? I looked under the car as best I could to see if anything was lodged anywhere, but I couldn't see anything, and if it were the brake pads, would they suddenly go out like that?

[justin9005]

you could have a back caliper sticking if the car is 4 wheel disc brakes your best bet is to take it into a shop. There can be a ton of causes for that maybe your front brakes are bad and they will grind and hardly stop your car and the back ones are the only ones that work causing it to ONly SLow the back end of your car

(look at your brake fluid if its low that means theres a problem with your braking system if its full then its gota b somin else with the brakes