The type of curtain rod that uses cords is called a traverse curtain rod. This type of rod has a cord mounted to a tension pulley on one side of the draperies. When you pull on the cord, the drapes open and close. The traverse rod has one or two master carriers with arms that travel along the rod inside a track. When the cord is pulled, the master carriers and their pulley system carry the drapes as they move. Restringing the curtain rod is something a homeowner can do.
Unhook the drapery pins from the slides and master carriers of the traverse rod. Put your draperies aside.
Remove the traverse rod from the brackets, and set the rod face down on the floor or a large table.
Locate a rectangular box that rolls in a track, which is the master carrier. If you have two carriers, locate the one with cord knotted at each end of the carrier. Use a marker to label this as master carrier A; label the second master carrier as B.
Cut and remove the cords and untie the knots. Traverse rod cording comes in one length and is typically not sold by the foot. Open the package and thread one end of the cord through the right side hole in master carrier A. Make a knot.
Bring the cord to the right and over the top pulley. Bring the cord back toward the left and between the top and bottom pulley. Thread the cord through the bridge of master carrier B. Continue taking the cord to the left and between the lower pulley and upper pulley.
Take the end of the cord up and over the top of the left side pulley and across to the right to the left side of master carrier A. Thread the end of the cord through the left side hole of master carrier A, and tie a knot. There should be a lot of excess cord on the left side of the left pulleys.
Remount your traverse rod in the brackets. Thread the cord into the tension pulley mounted on your wall. If you don't have a pulley, purchase one to improve the installation and function of your drapes. Install the tension pulley at least 6 inches above the floor and to the right side of your drapes.
Pull on the cord until the master carrier A is as far to the right as possible. Check your marks to be sure which carrier is which since you turned the rod when you installed it. Holding the cords taut, slide master carrier B as far to the left as possible. Lock the cord into the locking finger at the back of master carrier B.
Take up the slack in the cord by returning to master carrier A. Pull on the knot that is furthest to the right. Pull the cord as tight as you reasonably can, and tie a new knot as close to the master carrier A as you can. Test the operation of the traverse rod by working the cords. If everything is running smoothly, cut off the excess cord at master carrier A. Rehang your drapes.
Use a short ladder to better access the rod and drapes. Some traverse rod brackets use screws so a screwdriver may be necessary to remove the rod from the brackets.