Steel Wool
The track of the sliding door might have dirt build-up that would cause friction. Oftentimes, a distorted iron track can be the reason too. To fix these problems use a ball of old steel wool to remove the dirt build-up and sharpen the blunt edges of the track. If the iron track is in a bad shape you might have to call a professional and get it replaced.
Silicon Lubricant
There are special silicone lubricants for sliding glass doors that you can use to make sliding easier. The silicone-based lubricants are perfect for the sliding doors because they are non-sticky and avoid building up dirt. You can find it easily at a Home Depot or order one online.
To apply the silicone lubricant, clean the track of your sliding door and wipe it with a clean cloth. Spray the lubricant on the track and wipe the sides of the floor to avoid slipping on the floor.
Clean
Over time the tracks of the sliding door can get dirty and accumulate debris or small rocks that might interfere in sliding. If the glass door is not sliding smoothly, then it might need some cleaning. Use a vacuum cleaner to suck up the dust, debris, or small rocks. Inspect the track carefully to check if there are any stuck objects. Slide the door after cleaning, it should slide faster now. Use an old paintbrush or toothbrush to dust off the track if the problem persists.
