. SAFETY PRECAUTIONS FOR MAINTENANCE 2 - 34 The mater ial of these components naturally changes over time, and r epeated use causes deterioration, wear, and fatigue. A s a r esult, there is a hazard that these components may fai l and cause serious injury or d eath. It is difficult to judge the remaining life of these components from external inspection or the feeling when operating, so always replace them at the specified interval. Replace o r repair safety-critic parts if any replaceme nt time. defect is even when