Regularly pull out and clean the iRobot Roomba's front caster wheel. Pull firmly on the front caster wheel to remove it from the robot and clean the area inside if it has collected dust, hair or other debris. If the wheel has been damaged or worn out, you should replace it. Replacing the caster assembly is very easy and can be done without tools. This is an original iRobot part, part number 4624869 and suitable for all models of the iRobot Roomba 'e' and 'i' series.