My 2000 A4 has an issue with the rear passenger brake sticking. I have had my pbrake cable tightened recently, and last week i noticed about 3 inches of free play in the pull handle. My wheel gets super hot when driving around, and when this happens, my entire brake system fails. I can push the pedal to the ground, and must pump it 2-3 times to get the pressure back. When the car is cold, the brakes work fine. I am full on fluid, pads are fine.

Is the failure of my entire brake system a result from the overheating of my rear brake assembly? Corrective action?

 

The heat from a dragging brake boiled the fluid and expanded the line, dropping pressure. Tap it free to release it. You can spray it with a penetrating fluid and work it in by exercising the brake. It may fix it. If not you'll have to disassemble the cable linkage and actuator and find out why it's binding before you'll be able to fix it.