A broken zipper can be frustrating, especially when it happens on an expensive item of clothing, camping gear or luggage. Zippers themselves are inexpensive, but professional replacement can be costly and time-consuming. Though many modern zippers are self-repairing, malfunctions do occur. The most common zipper problem is a split -- a part in the zipper caused by a deformed zipper pull. When this happens, you can usually fix a split zipper with common household tools.
Gently pry the back of the zipper pull open with the head of a flat screwdriver. Once it will move freely, slide the zipper pull back over the split area. Position it directly before the split.
Crimp the bottom of the zipper pull with the pliers. Pinch each side of the pull evenly with firm pressure until the pull is back to its original shape.
Slide the zipper over the affected area and ensure that the zipper does not split apart again. If the zipper feels too tight, you can loosen it again slightly with the screwdriver head.
Extend the life of your zipper by always using the pull to open and close it. Never open a zipper by pulling on the fabric surrounding it, as this puts stress on the zipper mechanism. Don't force your zipper to close over an overstuffed purse or backpack. If fabric ever gets caught in your zipper, pull it out gently by hand before continuing to zip. Pencil lead and candle wax can both be used as rubbing agents to keep a zipper in good condition and prevent it from splitting or sticking. In an emergency, duct tape can be used to seal a zippered area until it can be replaced. Use duct tape only as a last resort, however, because the adhesive from the tape will stick in the coils of the zipper. If this happens, you will need to replace the entire zipper. If your zipper pull has completely detached from one side of the zipper, you can still fix it at home. Use a slight twisting motion with your screwdriver to pry apart the separated side of the pull. Realign the pull over the zipper, then clamp it together again using the pliers. Do not over-tighten.
Don't over-loosen or over-compress the zipper pull. The metal will weaken and eventually break if it is tampered with too much. Plastic zippers are often found on children's winter clothing, and are much less durable than metal coil zippers. A plastic zipper pull will break if you try to open it with a screwdriver. A split plastic zipper must be replaced.