Fixing a lock on a filing cabinet is a project that will involve a little work in tight areas. The locks come in two specific types. The first is the long pole-shaped device that locks multiple drawers at once. The second type is the individual drawer lock that is common for household file cabinets. Both of them have issues that are individual to the specific type of lock. Both will be examined so that you can make the repairs according to your particular cabinet.
Remove the lock from the drawer. Loosen the nut that holds the locking mechanism in place on the back of the lock.
Use the screwdriver to remove the coder pin that is holding the lock in place. It will push out toward the largest space. Wedge the screwdriver against the lock to allow for more pressure. Push the lock out through the front.
Place the new lock inside the hole and attach the new coder pin. It will push right in around the lock. This is done flush with the back of the drawer. Make sure that the lock is in an upright position when you insert the coder pin.
Place the locking mechanism over the bolt location. Attach the nut over the bolt and tighten. Test the lock to make sure it is flush and hold when the door is open. Make sure you test the turning before you test the door.
Examine the lock and mechanism. If the lock unit itself is bad, loosen the bolt that holds it to the long rod that actually locks all of the drawers. Remove the coder pin and pull out the lock. Place the new lock in the hole. Replace the coder pin and tighten back to the locking rod.
Examine the locking rod. If it is bent this is what is causing the problem. To replace it loosen the bolts at the top and bottom of the rod. The rod will fall to the back of the cabinet. Pull it out and put the new rod in. Place it in the holders and tighten the bolts.
Examine the locking rod and see if it is a pin or bolt type that locks all the drawers individually. If this is the case you will have to independently adjust the height of each hook or pin. Individually loosen each bolt slightly on each individual hook and adjust them about 1/16th of an inch up or down. Doing this can reveal the hook that is hanging up.