Carefully inspect the seat belt webbing; if it is cut, frayed, or damaged, replace the belt assembly. The front seat belt retractors are designed to lock and restrict belt movement when pulled quickly. If the operation of either seat belt is questionable, grasp the shoulder belt and pull sharply forward to check the shoulder harness for correct operation; a quick yank should lock the harness, and if the retractor does not lock during this check, replace it with a new one. Push the belt tongue into the buckle until an audible click is heard, then grab the two parts of the belt and yank on them to verify the locking ability; the belt should remain locked. Press the release button and note whether the buckle disconnects decisively. Check retractors for smooth operation by pulling each belt out and watching it retract; the retractor should reel it in smoothly and quickly. Finally, check all the anchor bolts for tightness and tighten them to the specified torque as necessary.