A pocket door off the track is retained by two moldings finished nailed or screwed to the face of the opening. To remove the door only one molding needs to be removed. Look at the top of the frame and check the track that the door hangs on. There should be a “J” track that the door rollers run on.
The molding you need to remove is the one on the long side of the J. Use a mini-wonder bar to loosen and remove the molding.
Now swing the door sideways and lift slightly so the wheels come out of the pocket door track. Inspect the wheel assemblies at the top of the door. Chances are the wheels are loose or chipped and need replacing.
The pocket door track could be bent or filled with dirt. If it is badly bent you have problems. The hardest thing to fix is a bent track because it goes into the wall as far back as the door is wide. Replacing it requires cutting holes in the wall to access the screws holding it to the header.
The good thing is you will use the same access holes to re-install the new track. We sell an adhesive wall patch that makes repairing an eight-inch hole easy in only three light coats of spackling or joint compound.
If the track is not bent, take a coat hanger or some other long, thin tool that you can attach a cloth to. Use it to drag dust and dirt out of the track as far back as you can reach. The crud in the track is usually the cause of poor door operation in the first place.
Do not oil or lubricate the track. That would be like oiling the ground because your “wagon wheel squeaks.” Put a drop or two of oil, no more, on the axle of the wheels before reinstalling the pocket door. That should provide another 10 years of smooth and quiet service.