My TriStar CXL PN brush roller seems to slow down greatly; I had put on a new genuine Tristar flat belt & made sure all the seals & washers are in place. Also, the PN makes a high-pitched squeal. Could the motor be going bad?
High pitch squeal uh oh sounds like the bearing are going buddy i would get a new motor if its slowing down but i would try it whit out the brush roll first and see if the motor makes any improvement if not your motor is on its way out .
Well, if it has a high pitched squeal, there has to be something that is causing friction between the belt and the brush roll, if not, the motor bearings are going bad. Try to replace them if you can.