there are specific limits to the widths of the front disc and rear drum, measured with a precision tool. better had look up these values in a factory manual, compare and check to see if they are out of spec. other than that your rotors are warped . cheap chinese replacements can be bought on ebay.
you can also tighten up the slack on your rear brake cable to that there is less pedal travel but the rear brakes are not touching.
Silver 2000 Firefly 4DR; 16V SOHC, 3 to 5 speed swap, install PS and AC, remote and auto start, PL, PW, kill and start switch, Valentine 1, behind-bumper CAI, 55MM TB with coolant-bypass, polyurethane-fill engine/shifter mounts, modified to short shifter, upgraded electrical system, CS130 alternator, 90/160W headlights + relay mod, ceramic H4 plug/harness
To do: finish stereo, 4000K H4 HIDs, short block replacement
'sponsored' by Captain Crunch, Lordco, Felpro, Permatex, Royal Purple