How to Stop Motor Brushes from Sparking?

sparking power tool in factory

Why are the motor brushes sparking?

If your motor brushes are sparking, it may be a sign excessive brush wear, a damaged or dirty commutator, or an incorrectly installed or incompatible brush.

Some sparking is normal within a tool, but if it starts to get worse, it's likely a sign that the carbon brush is wearing.

To monitor the sparking from your tool, you can check the air vents when in use, and this helps you to gauge how much the sparking has changed over time.

When checking for sparking or arcing, a decent observable examination of the commutator and brushes will have to be conducted.

What could be the cause of the sparking?

Check to see if there is a loose carbon brush cap, or any excessive dirt or bits in the mechanisms that could stop the brushes from working correctly.

If there is excess sparking (arching) this could be a sign for the carbon brushes not having proper contact against the commutator (the copper segments) and means that there could be a possibility of wear of the commutator.

if this is the case once its been diagnosed by a professional tool repair technician then you may need to change the armature.

If after inspecting your carbon brushes you notice signs of breaking, crumbling or burning; then it's definitely recommended to replace the armature immediately as no amount of brush changing will help.

If there is a discolouring on the spring such as a rainbow pattern, then it could be a sign of broken lead in the spring, which indicates a replacement is needed.

If the spring has collapsed completely, then you definitely need a new brush.

How long can I wait when I notice motor brushes sparking?

You shouldn't leave worn brushes in a tool for very long, as they can damage the armature which is very expensive to fix.

Top Deals Online is a UK based supplier of replacement carbon brushes, where you can search for the exact brush to fit your tool by model and make. Click here to learn more.

Preventative Measures

To stop your motor brushes sparking as quickly next time, you can take prevenative measures to prolong their life.

Ensuring your motor brush is the right size and specification for your tool will help to avoid excessive wear through a loose or tight connection.

Proper care and maintenance of your tool, including cleaning, will ensure no debris causes excess friction.

About the author

Harry — Owner, Top Deals Online

Harry is the owner of Top Deals Online and the author of its workshop guides. He has spent more than 15 years in the spare parts trade, specialising in carbon brushes, following more than 32 years in retail — including DIY stores, power tool sales, and electrical goods.

Harry’s knowledge comes from the work itself: matching brushes to exact tool models, and sourcing and manufacturing brushes to his own specification through long-standing supplier relationships worldwide — all made to RoHS standard and meeting UK and EU requirements. That hands-on experience means he knows how a brush is formed, ground, measured, and wired, not just what a spec sheet says.

Over the years he’s tracked down discontinued and hard-to-find parts that customers couldn’t get anywhere else, for home users and commercial repairers alike. Top Deals Online runs from London on precise advice, fast delivery, and verified customer reviews.


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