My brakes are acting weird?

I was driving home and coming to a red light, pressed on my brakes a little,and nothing happened. I had to press them all the way to the floor in order to get them to work. Do i just need the brake fluid changed or is thisa bigger problem. And how much will this cost me. I am a poor college student.My brakes are acting weird?make sure your fluid is full if it is then its the master cylinder what make model and year is your car and i'll give you the price of the part and a link to it.My brakes are acting weird?can be a couple things, master cylinder, or a line leaking. Pump the brakes and see if the pedal seems to come up higher. then check your brake fluid level. if your fluid is full, then more likely master cylinder, if the breaks did not pump up and you are low on fluid, then possible you have a line leaking. check for brake fluid on the ground around each tire.My brakes are acting weird?Go and have a mechanic diagnose the brakes before you're a poor DEAD college student. Changing brake fluid won't make the car stop better. Brake pads, rotors, and possibly calipers if they are frozen. Master cylinder is possible, check the fluid.My brakes are acting weird?you might need brake fluid or if you have rear drum brakes they might need adjusted.it also could be the master cylinder.