求翻译：5.教练车底盘的保养，要重点更换行走部分润滑油，一定要更具温度换适合地润滑油，不要换质量低略的钙基润滑脂，刹车油要重点检查，因为温度对刹车油有重要影响，温度引起黏度变化，而黏度变化影响刹车的性能。是什么意思？

5. maintenance of coach chassis, we should focus on replacing the undercarriage lubricants, be sure to have more temperature-for suitable for lubricating oil, not for the low quality of calcium base grease, brake oil to focus checks, have an important influence because of temperatures on brake oil, viscosity caused by temperature and viscosity affect the performance of the brake.