The motor brush conducts electricity across the commutator/armature. The carbon brushes are about 3/4 inches long when new and wear down with use. The goal is to change the brush before the brush holder tears into the commutator. If the commutator is not smooth do not replace the brush, replace the motor. Normally, check motor brushes every couple years and replace when down to 3/16". The brush is flat but breaks in during use to match the curved surface of the commutator.
How to Check and Replace Carbon Brushes.
Carbon Brush fits Lamb Ametek Vacuum Motors: 115330, 115334, 115684, 115837, 115937, 115950, 115962, 116103, 116119, 116136, 116137, 116139, 116161.
Color may vary. Male flag terminal is 1/4 inch.
SOLD INDIVIDUALLY, price is for a SINGLE brush.