Aquabot Extreme no longer follows cleaning pattern

by Chris
(Massachusetts)

My Aquabot Extreme is 4 years old. It no longer follows the cleaning pattern it used to. Basically just goes back and forth without adjusting direction. The drive belt and tracks have been replaced within the last 2 years. I have never replaced the brushes. Could this be the problem? Other than this, the unit pumps water, climbs walls, and cleans well.