A: Much like the timing belts in your car, a vacuum belt needs to be changed as well. However, a vacuum belt should really be changed about every 3-4 months. When belts stretch they no longer turn the brush roll at the proper speed for maximum cleaning. One way to tell if you’ve waited too long, is if you hear a squeaking sound when you start up your vacuum. If you really wait a long time, you’ll even start to smell something burning. Quick, change that belt!