I have a 2003 Super Duty 4X4 with a 6.0 and my rear brakes have stopped working. The pedal is hard and the front brakes stop the truck but no fluid comes out of either wheel cylinder when a bleed attempt was made. I was told that my ABS control valve or module is stuck. Can someone tell me how to fix it and/or should I replace it. OEM dealer cost is $999 and $500 for the computer,,,,, ouch!