How to Replace the Carbon Brushes on a Makita Grinder

Your grinder's motor uses two carbon brushes to conduct electricity to the armature. The brushes do this through the armature's commutator. The carbon brush will wear down over time (from rubbing against the rotating commutator) and will need to be replaced. Worn brushes can cause excessive sparks around the commutator. The sparks can also be caused by a damaged armature, so you'll want to carefully inspect both components if sparks are present.

Let's get started.

REMOVING THE CARBON BRUSHES   1. Remove the carbon brushes.

a. Use a large screwdriver to loosen (and remove) the brush caps.

b. Remove the carbon brushes from the brush holders.

INSTALLING THE NEW CARBON BRUSHES

  2. Install the carbon brushes.

a. Install the new carbon brushes into the brush holders.

b. Secure the carbon brushes with the brush caps.