Check the rail (or track as some people or manufactures call it). The rail could be fouled with some kind of debris. (Some manufacturers provide a lubricant that is applied at installation.) This lubricant can collect grime over time, causing problems with door movement.
Use a grease-cleaning product to fix this problem.
Fixing corrosion may require replacement of the rail section or the entire door.
Check the rollers themselves - sliding the door can also be hampered by problems with the rollers. Check to see whether the roller may need a drop of lubricant on its axle. Years of use can cause worn spots on the surface of the rollers, making the door difficult to move.
See whether adjusting the track cover that comes with some models stops the problem.
Consider replacing the entire unit - this may be the best option to get rid of an older or inferior product.
Things You Will Need
- Lubricating Oils
- Screwdriver Sets
- Some rollers are made to be replaced, others may require replacement of roller and mounting bracket assembly.