The most common cause of emergency brake failure is the rubber hose covering the cable wearing through. When this happens, water, road salt and other debris will get on the metal cable and rust it until it is so weak it breaks. Unfortunately, an emergency brake only reveals its need to be fixed after you have needed it, and it failed to engage. You don't need to pay a mechanic to fix an emergency brake; it's a job you can do yourself in a couple of hours
Pull the boot off the floor that covers the bottom of the emergency brake handle. If your boot is plastic, you will only need to pry up on the bottom of the boot with a flat head screwdriver to loosen it. Once the bottom is loose, pull it up and off the handle. For a leather boot, unlace or unzip the leather and pull it off the handle.
Pull on the two cables coming from the base of the emergency brake handle and going out to the underneath of the car. The cable that is slack is the one that needs to be replaced. Each cable runs to one of the rear tires. The tire it goes to will match the side of the car the cable is closest to (i.e., passenger side to rear passenger tire).
Loosen the lug nuts on the tire that the broken cable goes to with a lug wrench. Raise the car on a tire jack. Transfer the weight of the car to jack stands, remove the lug nuts and then remove the tire so you can access the wheel drum.
Reach behind the wheel drum and pull on the emergency brake cable that is connected to the drum. Each side of the emergency brake system actually consists of two separate cables. The cables from the handle run straight back to the equalizer bar. There are two cables that come off the bar, one going at an angle to each brake. If you pull on the cable connected to the brake drum and it is loose as well, then you must replace both parts of the cable. If it is not loose, then you only have to replace the cable from the emergency brake handle to the equalizer bar.
Remove the broken cable line. Using a socket wrench loosen the tension nut holding the cable to the emergency brake handle. When it is loose, pull the cable out from the nut. Loosen the anchor nut on the equalizer bar and remove the other end of the cable from there. The anchor end of the cable has a metal stop pressed onto it. If you have to remove the cable that runs to the wheel drum, remove the drum by removing the bolts attaching it to the axle and pulling it off; then loosen the tension nut holding the cable inside the brake mechanism.
Replace the broken cable with a new one. Install the anchor ends at the equalizer bar first, then pass the cable through the tension nut, hold the cable tight with a pair of vise grips and tighten the nut into place. You do not need a lot of tension on the cable, but it should feel firm to the touch; and when you move the handle, the cable should not slide back and forth in the nut but should engage the emergency brake.
