Carbon
the reason for brushes is to makethe motor revolve. The more brushes probably make a more powerful starter motor
Its not worth replacing the starter motor brushes on any car. By the time the brushes are worn, there is probably other wear and tear to the bearings, the commutator, and the windings. Better to just replace the starter. Same deal with the brushes in an alternator.
In a 1997 Toyota Prado starter, the brushes are located inside the starter motor assembly, specifically within the starter's end housing. To access them, you typically need to remove the starter from the vehicle and disassemble it by removing the end cover. The brushes make contact with the armature and are crucial for the motor's operation. If they are worn out, they can cause starting issues and may need replacement.
A brush is made out of carbon.
Carbon is much stronger and because the motor commuter is spinning copper brushes will wear off quickly.
replace the starter
the starter is bad and has an internal short That answer is simplistic. On my '98, for months I could hit the starter and make it work. When I actually removed and disassembled the starter, one of the brushes was worn out. Hitting the starter moved it just enough to contact the commutator. Installed new brushes three years ago and haven't had any problems since.
To repair a Deutz starter motor, first, remove it from the engine by disconnecting the battery and unbolting the starter. Inspect the motor for common issues such as worn brushes, a damaged armature, or a faulty solenoid. Replace any damaged components and clean the internal parts to ensure proper contact. Finally, reassemble the starter, reinstall it, and reconnect the battery to test its functionality.
Starter motor may not be ok. The starter motor brushes may be worn down to allmost nothing. You didn't say what vehicle you have but another possilbility could be the starter solenoid. Also be sure your battery and battery connections are clean and tight. Have a look at www.carbasics.co.uk There are lots of help articles in their 'how to section'.
the brush is a peice of carbon that is attached to the startor by a brush holder.
dying battery, bad ground, starter brushes. take your pick
The starter is just a DC motor so the motor gets dirty inside or the armature and brushes wear. If the battery is good and yet you just hear a click or nothing or even the starter spinning, the next most likely cause is the starter motor. They are cheap to replace yourself, though the job is a little tight. See wikianswer on 1993 Ford Escort for the process.