Ryobi is a tool manufacturer specialising in hand-operated power tools such as drills, sanders and small saws. They also offer a line of hand-held angle grinders, which operate on 110 power with a sealed-bearing motor. The motor has a pair of brushes that can wear down over time, causing the motor to stop functioning. You can replace the brushes on a Ryobi grinder in a few minutes with nothing more than a flathead screwdriver.
Disconnect the Ryobi grinder from the electrical socket.
Insert a flathead screwdriver into the brush cap on the left side of the motor housing, just in front of the trigger. Turn the cap counterclockwise to loosen and remove the cap. Be aware that the brush beneath the cap is spring-loaded, so the cap will want to pop out of the hole when loose.
Set the brush cap to the side. Pull out the brush and spring, noting the orientation of the brush.
Insert a new Ryobi brush and spring into the opening in the same manner that you removed the damaged brush. Depress the spring and place the brush cap over the spring. Tighten the cap in place with the flathead screwdriver.
Repeat Steps 3 and 4 with the brush cap and assembly on the right side of the angle grinder.
Plug in the power cord to the outlet to test the grinder.