How to inspect and replace golf buggy motor brushes
Written by the Hawke Electric Vehicles Service Team
Quick answer
Replacing golf buggy motor brushes means isolating the battery pack, opening the commutator end of the motor, comparing each brush against the minimum length in your manual, then fitting new brushes, checking the springs and cleaning the commutator before you seat them. It is an advanced job that takes one to three hours depending on whether the motor comes off the vehicle, and it needs basic hand tools plus the correct brush set.
Tools needed
- Digital multimeter
- Socket and spanner set
- Insulated gloves
- Safety glasses
- Fine abrasive pad or commutator stone
- Compressed air or a soft brush
- Small spring scale for spring tension
- Ruler or vernier caliper
Parts needed
- Matching motor brush set for your motor
- Brush spring set if springs are weak
- Electrical contact cleaner
What this fixes
Worn or sticking motor brushes cause a range of familiar symptoms: a buggy that has lost power or top speed, that hesitates or surges under load, that squeals or grinds from the motor, or that cuts out and comes back as the worn brushes lose contact with the commutator. Brushes are a wearing part, so replacing them at the end of their life restores clean, steady contact and full power. This procedure covers the brushes, springs and commutator surface; it does not cover a shorted armature or failed bearings, which are separate motor faults.
Tools and parts
Parts
- Motor brush set matched to your motor
- Brush spring set, if the springs have weakened
- Electrical contact cleaner for the commutator
You will need a multimeter, a socket and spanner set, insulated gloves, safety glasses, a fine abrasive pad or commutator stone, compressed air or a soft brush for the dust, a small spring scale to check spring tension and a ruler or vernier caliper to measure brush length. This is an advanced job because access is tight and the brushes must be seated correctly, and it takes one to three hours. Always buy the brush set specified for your motor, and always read the wear limits and spring figures from your motor or vehicle manual rather than guessing them.
How to do it
1Isolate the pack and disconnect the motor leads
With the pack isolated and the capacitors given time to discharge, label and disconnect the heavy motor cables so you can turn the motor or remove it. Take a photo of the wiring before you start.
ExpectedThe motor is de-energised and its leads are labelled, so nothing is live and reassembly is unambiguous
2Reach the brush end of the motor
Locate the commutator end of the motor, which is the end opposite the drive shaft, and remove the cover band or end cover that hides the brushes. On some vehicles you can do this in place; on others the motor has to come off first.
ExpectedThe brushes, springs and commutator are visible through the opening
3Inspect and measure each brush
Lift each brush spring in turn, slide the brush out of its holder and measure its length, then compare it against the minimum in your manual. Brushes are commonly renewed once they wear to roughly a third of their original length or reach a moulded wear mark, but the manual figure is what counts.
ExpectedAny brush at or below the manual minimum, chipped, oil-soaked or worn at an angle is due for replacement; replace the full set together
4Check the springs and the commutator
Check each brush spring for full tension with the spring scale against the manual figure, and look at the commutator: it should be smooth and an even brown, not scored, blackened or with solder thrown between the segments. Blow or brush the carbon dust out.
ExpectedSprings within the manual tension range and a clean, even commutator; weak springs are replaced, a lightly glazed commutator is dressed in the next step
5Dress the commutator if needed
If the commutator is glazed or lightly scored, dress it with a fine abrasive pad or commutator stone while turning the armature by hand, then clean off the dust with contact cleaner. Deep scoring or a stepped commutator is a job for a motor shop.
ExpectedA clean, matt, even commutator surface with the gaps between segments clear of debris
6Fit the new brushes and springs
Slide each new brush into its holder the correct way round so its face matches the curve of the commutator, refit or replace the springs, and make sure each brush moves freely in its holder without sticking.
ExpectedEvery brush sits square against the commutator, is held firmly by its spring and slides freely in the holder
7Reassemble and reconnect
Refit the cover band or end cover, remount the motor if you removed it, reconnect the labelled motor cables to the correct terminals and torque them to the figure in your manual, then reconnect the battery pack positive first and negative last.
ExpectedThe motor is buttoned up, the cables are on the right terminals and tight, and the pack is reconnected in the correct order
Check it worked
8Bed in the new brushes and test drive
Raise the drive wheels clear of the ground on axle stands, restore power and run the motor at low speed for a few minutes to bed the brushes in, then lower the buggy and take a short, gentle test drive.
ExpectedThe motor runs smoothly and quietly, power and top speed are restored, and there is no squeal, surge or cut-out; the brushes bed in fully over the first few miles
When to book an engineer
Book an engineer if the commutator is deeply scored, stepped or has thrown solder, if the motor still runs rough after new brushes, or if you find scorched windings or a burnt smell, because those point to an armature or bearing fault rather than the brushes. Pulling and pressing a motor, skimming a commutator and testing an armature for shorts all need equipment beyond hand tools. If the motor comes off the vehicle and you are not confident refitting the drive coupling and torquing the cables correctly, that is also a fair point to hand it over.
Common questions
How do I know the brushes are worn out?
Pull each brush and measure it against the minimum length in your manual. Alongside that, look for brushes worn on an angle, chipped, oil-soaked or so short the spring is nearly bottomed out. Loss of power, surging under load, squealing and intermittent cut-outs are the driving symptoms that send you to check them.
Should I replace all the brushes at once?
Yes. Brushes wear together, so fitting a full matched set keeps contact even across the commutator. Mixing a new brush with worn ones leads to uneven wear and uneven current sharing, which shortens the life of the new brush.
Do I need to clean the commutator too?
Usually. A light glaze can be dressed with a fine abrasive pad or commutator stone and cleaned with contact cleaner. A commutator that is deeply scored, blackened or stepped needs skimming on a lathe, which is a motor shop job, not a driveway one.
How long do golf buggy motor brushes last?
It varies widely with use, load and terrain, so treat any single figure with caution. Hilly ground, heavy loads and hard acceleration wear brushes faster. The reliable answer is to inspect them at service intervals and measure rather than assume a mileage.
Why do the new brushes need bedding in?
A new brush has a flat face, while the commutator is curved, so at first they only touch across a narrow strip. Running the motor gently for a few minutes, then driving lightly for the first few miles, wears the brush face to match the commutator and brings contact up to full area.
Can worn brushes damage the motor?
Yes, if left long enough. A brush worn down to its spring or its lead can arc and score the commutator, and the arcing and heat can blacken or step the surface, turning a brush job into a commutator or armature repair. Replacing brushes on time avoids that.
Did this fix it?
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