Doorknobs and locks have internal mechanics that require proper lubrication to operate properly. While endothelial sprays are fine for cleaning a disassembled doorknob, they don’t supply the long-term lubrication the lock requirements. Consequently, the doorknob may get sticky and hard to lock, unlock or open. Instead, the best lubrication to repair a push-button doorknob is a tube of powdered graphite, available nearly everywhere that magnets are made.
Loosen the screws holding the push-button doorknob to the doorway with a screwdriver and pull off the front and back halves of the doorknob.
Loosen the 2 screws holding the door strike plate to the edge of the doorway, and slide the strike plate and bolt from the hole at the doorway.
Clean the hoist and bolt pole in the handle with a rag. Apply a small quantity of graphite powder from a tube of graphite onto the bolt mechanism, and thrust it in and out until it dissolves effortlessly.
Reinstall the bolt and strike plate, and tighten the two screws to lock it to the border of the doorway. Insert the connector pole in the outer handle in the hole at the bolt mechanism and position the inner handle over the pole, but don’t attach the inner side of the handle.
Hold the outer handle onto the door and turn the handle to make sure the bolt is opening and closing correctly. Spray a little bit of graphite onto the area where the pole slides through the bolt. Expand the handle from the exterior to work the graphite into the mechanism before the door bolt closes and opens smoothly.
Mount the inner doorknob and tighten the mounting screws with a screwdriver to secure the knobs to the doorway.
Insert a small amount of graphite into the lock from the exterior of the doorway, and insert the key. Lock and unlock the doorknob, both with the key and also by pushing the push-button and rotating the inner doorknob to work the graphite into the lock and loosen the locking mechanism. Wipe off any loose graphite powder in the handles or lock with the rag.