Hammer Drill: Hammer Drill Mode is Weak or Drills too Slow
If your hammer drill mode is weak or drills too slow, check out the following parts: the carbon brushes, switch, grease, and selector switch. Make the repair yourself by following our repair guide. Your hammer drill will be working at peak performance again in no time. Refer to your owner's manual for detailed instructions on your model.
To inspect your carbon brushes, remove the handle and open the case of the drill. This will vary as they are all different. With the case open, locate the brush holders and proceed to remove the holders by gently pulling up on them. On some models, release the hold-down clip and pull the brush out of the holder. Brushes 1/8 of an inch, or less, are considered worn and will need to be replaced. Install the new brushes in the holder and make sure they lock down. On other models, slide the brush into the holder and reapply...
To inspect your carbon brushes, remove the handle and open the case of the drill. This will vary as they are all different. With the case open, locate the brush holders and proceed to remove the holders by gently pulling up on them. On some models, release the hold-down clip and pull the brush out of the holder. Brushes 1/8 of an inch, or less, are considered worn and will need to be replaced. Install the new brushes in the holder and make sure they lock down. On other models, slide the brush into the holder and reapply the hold-down clip. Tuck all wires in their channels and reassemble the case back together. Finally, reattach the handle.
To check the switch, remove the handle and open up the case of the hammer drill. All models are different, so this will vary. Begin by examining the carbon brushes to make sure they are not worn out as they can cause the same symptoms. See “carbon brushes” for removal and installation. Once you have determined the brushes are fine, proceed to remove the switch.
There may be a hold-down bracket, or screws, securing the switch down. Inspect the switch for any melting, or burning marks, indicating a malfunctioning switch. Inspect the condition of the wires and connectors at...
To check the switch, remove the handle and open up the case of the hammer drill. All models are different, so this will vary. Begin by examining the carbon brushes to make sure they are not worn out as they can cause the same symptoms. See “carbon brushes” for removal and installation. Once you have determined the brushes are fine, proceed to remove the switch.
There may be a hold-down bracket, or screws, securing the switch down. Inspect the switch for any melting, or burning marks, indicating a malfunctioning switch. Inspect the condition of the wires and connectors at the switch as well. Remove the connectors and transfer them on the new switch – careful not to mix up their position. Install the new switch in the drill case and reattach any hold-down screws, or brackets, securing the switch. Tuck wires into their appropriate channels. Reassemble the drill case back together and reattach the handle.