Spray the inside of the track with a Teflon or silicone lubricant spray. This will slick down the surfaces of the track and allow the door to slide. After the track is sprayed, scrub the interior track with fine steel wool to remove any grime that could cause the door to get stuck inside the track.
The rollers on the bottom of the screen door get worn out from use and grime. This causes them not to spin freely and the screen to stick. Clean the rollers in place using a toothbrush and a can of compressed air while the door is still in the track. Then spray the rollers with silicone lubricant.
To remove grit from the track, you will need to remove the sliding door. Grit will cause the rollers to wear down prematurely and cause the rollers to stick inside the track. Lift the bottom rollers on the sliding screen door out of the track with your hands, then set the door aside. With a soft brush or vacuum extension, remove any grit inside the track.
After the screen door is removed from the track, pry the wheel from the channel with a flat head screwdriver. In some cases, the wheel is screwed in place and must be screwed off with a Philips screwdriver. Pour a grease-cutting detergent and water in a bowl, and soak the wheels in the solution for 15 to 20 minutes. Before reinstalling them, spray the rollers with a silicone lubricant.