Brakes on Ford Taurus 1994 Sedan

Hi

I had the brake light indicator on the dash board light up although the brakes were released a few months ago. I filled it with DOT3 and the problem went away.
But today while taking the car out the brake seems to have failed. When I brake the car takes longer to stop and also I have to press the brake pedal to the floor to stop the car. When I drive the car at 50Kmph and try to stop it suddenly the car shakes. The brake light has started to light up again.
Could someone tell me what I have to replace to get it back in shape.

Thanks
Harold

You probably have a brake line that has expanded preventing your brakes from working properly. Instead of compressing the piston, they're just ballooning up the line.