How often do vacuums need a new belt?

My vacuum cleaner is not picking things up well. I have a new bag in it. I'm wondering if it needs a new belt, it hasn't had a new one since we bought it about 4 years ago. How often do vacuums need a new belt? Is there another part of the vacuum that may need cleaned or repaired to help it work better?How often do vacuums need a new belt?Normally you only need a new belt when you run over something with the beater brush and it causes it to lock down and makes the belt stretch or break. Turn it over to see if the brush is turning and also feel or use a large piece of paper over the opening to see if you're getting good suction.How often do vacuums need a new belt?check it..it could have broke..usually it is replaced just when it breaks..but i guess it could come looseHow often do vacuums need a new belt?It needs a new belt if it breaks or stretches. If your beater brushroller is spinning the belt is fine. Heres a link of things to check. Good luck