How to Repair or Replace the Plug in Your Pin Tumbler Lock
The pin tumbler lock is also known as the Yale lock, and is probably one of the best known locks in the world. The lock functions using a cylinder tube inside. This tube is also known as the Plug. This links to a mechanism which locks the door. Your key fits into the plug and moves around small pieces of metal, known as pins, which then are used to turn the mechanism of the lock. Each Yale lock is different, so if you find that you have broken the plug part of your door lock, you will either need to repair the plug, or replace it with a completely new one.
Step 1 - Make a Mold of Your Key
In order to repair the plug, you will need to know where the pins should be in relation to your key. You can do this by keeping the key in the lock, but you may find that you risk breaking it off should you run into problems. A better alternative is to make a mold of your key out of wire. Heat the wire slightly to make it malleable and fit it around the edge of the key. Make sure that you get every part of the key's profile, as they will all be necessary to make an impression on the lock.
Step 2 - Remove the Lock
Unscrew the lock from the back of the door and lay it flat on the table. You should be able to leave the key access point in the door to be reconnected to the lock later. If you want to, you can remove this and leave it to one side in case you have to replace the plug completely.
Step 3 - Remove the Plug
Unscrew the lock and remove the cylinder from the middle. Examine it for signs of damage or rust. These can easily be cured by adding a liquid cleaner to the middle of the plug. Insert the wire key mold into place and then open the cylinder. The pins should be on one side of the barrel with the key mold keeping them in place. You can lift out and lubricate each one and then screw the plug back together.
Step 4 - Replace the Plug
If this does not work, remove the plug from the springs attached to it and discard. Take a replacement plug and insert it into the lock, replacing the springs as you do so. You may need to screw it into place on the lock before you can proceed. Take the replacement lock attachment which fits the plug and insert this into the door from the outside in. Screw this into position and then place the lock mechanism into the door. You should screw this back into place as well.