Sliding glass doors are meant to slide. When they don't, they become see-through walls. If your door bumps along the track or jumps completely when you open and close it or is just hard to pull, there is a good chance you need a complete sliding door track replacement.
The mechanism that lets the door slide freely along the track is simple and restoring it to its original condition is usually simple as well. The type of repair you need to perform depends on the symptoms your door exhibits.
Remove dirt and debris from the track with a wire brush. With the door in the closed position, scrub the surface of the track paying special attention to the raised wheel guides.
Any obstruction on the track will prevent the wheels from operating smoothly. This should be done as soon as the door pulls roughly or feels like it is rolling over gravel when opening or closing.
Clean the loose debris with a vacuum cleaner or broom. Move the door to the fully open position, scrub the exposed track with a wire brush and remove any loose dirt with a vacuum cleaner or broom.
Remove the door from the track. Open the door about halfway, lift it straight up and pull the bottom toward yourself until it is free of the track. Keep a firm grip on both edges of the door while you do this.
Sliding glass doors are kept in place by the track on the bottom and a simple channel guide at the top of the frame. Once clear of the bottom track, the door will drop out of the frame completely.