Most sliding closet and patio doors operate on rollers at the bottom and the top of the door. Occasionally, these rollers get clogged with dirt and debris, which can cause the door to jam up during opening and closing. To repair a rolling door, use the following steps.
Open the door and give the upper and lower track a good clean. Vacuum the track with a brush attachment and clean out any debris with soap and water. Apply lubricant to the tracks.
To adjust the height of the rollers, find the adjusting screws. These are usually located at the bottom face or edge of the door. Most doors have two screws. Turn one to adjust one roller and even out a lopsided door. Turn both of them to raise the entire door.
If cleaning the tracks and adjusting the hardware don't fix the door, remove the door and clean out the rollers themselves with a stiff brush. Spray some aerosol lubricant on the rollers to help them slide along the tracks.
If any of the rollers appear to be broken, remove them and install replacement rollers. Put the door back onto its frame.