1997 Ford Expedition Owner's Manual - Page 211

Maintenance and care Cleaning and maintaining the safety belts Clean the safety belts with a mild soap solution recommended for cleaning upholstery or carpets. Do not bleach or dye the belts, because these actions may weaken the belt webbing. Check your safety belt system periodically to ensure that it works properly and isn't damaged. If the webbing shows any signs of wear, nicks or cuts, have it inspected by a qualified technician to determine if replacement is necessary. Always have your safety belt system checked after a collision by a qualified technician. All safety belt assemblies, including retractors, buckles, front seat belt buckle support assemblies (slide bar if equipped), child safety seat tether bracket assemblies (if equipped) and attaching hardware should be inspected after any collision. Ford recommends that all safety belt assemblies used in vehicles involved in a collision be replaced. However, if the collision was minor and a qualified technician finds that the belts do not show damage and continue to operate properly, they do not need to be replaced. Safety belt assemblies not in use during a collision should be inspected and replaced if either damage or improper operation is noted. 212