Cordless vacuum produces a high‑frequency squeal from the floor nozzle when the brush is on

Safety first: Remove the battery and detach the nozzle.

• Remove brush roller: Take out the roller and inspect the end bearings or bushings. Clean out dust and hair.
• Lubricate lightly: If the bearings are not sealed, apply a tiny drop of light machine oil to the bearing surfaces. Do not over‑lubricate, as excess oil attracts dust.
• Check for wear: If the roller wobbles significantly or bearings feel rough, replace the brush roller.
• Reassemble and test: Ensure the roller is correctly seated and the access cover is fully closed before testing.