How to Repair a Sliding Door to Keep It Working Like New

To begin, you’ll need to prepare to remove the door by locating the roller adjustment screws. There are usually two screws at the bottom of the door on the inside face that control the height of the rollers and the height of the door within the frame. Turn these screws counterclockwise to retract the rollers, which will make it easier to remove the door.

Next, you’ll need to remove the molding found at the top of the door. This is the piece of trim that prevents the door from falling inward. Unscrew the screws holding the molding to the door frame, then pull the molding off the frame. Once the molding has been removed, the door is no longer secure in the frame and can fall easily, so be sure to have someone supporting the door to keep it safe and steady.

Along with your helper, carefully tilt the door in toward you and lift it out of the bottom track. Set it on sawhorses so that you can more easily perform any necessary repairs. After the door has been removed from the frame, clean the bottom track thoroughly with a vacuum, ensuring no debris remains.

Once the door is off the track, examine the rollers. If there is dirt or debris caked in the roller mechanism, scrub it off with a small cleaning brush, then wipe all roller surfaces down with alcohol to remove any remaining dirt or residue. Once the roller is clean, lubricate it with a silicone-based lubricant, which will resist dirt and keep the roller gliding smoothly.

If the rollers are bent or damaged, they can be easily replaced. First, check the door manufacturer’s instructions to make sure you’re using the appropriate replacement rollers. Next, unscrew the rollers from the door and gently pry the assembly out with a screwdriver. Install the new rollers, being sure to align the adjustment screws with the corresponding access hole in the door. Once the rollers are replaced, use the adjustment screw to fully retract them so the door can be reinstalled.

Over time, weatherstripping can deteriorate, get torn or misshapen, or come loose from the door. Check to see if your door’s weatherstripping is in good shape, and if not, gently pry the old weatherstripping off the door and replace it with new material. Different types of weatherstripping may be affixed with screws, staples, or adhesive, so follow the instructions carefully to be sure you’re installing it correctly.

Once you’ve completed any necessary repairs, it’s time to put the door back on its track. With your helper’s assistance, set the bottom of the door in the lower track and tilt it up until it’s aligned at the top of the door as well. Screw the stop molding back on while your helper holds the door steady. Remember: the door isn’t secure until it’s both in the lower track and held in place with the stop molding. 

When the door is successfully reinstalled, close it almost all the way so you can adjust the latch alignment to the target on the jamb. Use the roller adjustment screws to lift the door to the right height so the latch hits the jamb correctly. Remember to adjust both rollers so the door is level.