How to Change Carbon Brushes in Leister Tools

Tools needed:

• Contact cleaner or rubbing alcohol
• Cotton swabs
• Small flat screw driver
• Torx screw drivers, T10 and/or T20, as needed to disassemble the tool housing

Steps:

​Note: Always change both brushes at once. If one brush needs to be changed, change them both.

1. Cool down the tool and unplug it.
2. Disassemble the housing to expose the brush holders.
3. Check the brush holder tabs to see if the folded area is creased or cracked. If so, the tool must be sent to STANMECH to have the brush holders changed.
4. Use the small flat screw driver to carefully lift the brush holder tab 90 degrees.
5. Pull out the brush carefully. Be careful not to pull the spring off of the brush or it will be more difficult to remove the brush.
6. Clean the brush holders with a cotton swab and contact cleaner or rubbing alcohol.
7. On rare occasions, the inside of the brush holder may be scratched, roughed, or dented in. To check this, wipe the brush clean and slide it in and out of the holder. If the brush catches badly, the tool must be sent to STANMECH to have the brush holders changed.
8. Replacement brushes must be matched to the exact tool model, date code and voltage rating. If you are uncertain which brushes are correct, call STANMECH with this information and we will advise on the correct part number.
9. Place the brushes in the brush holder and use the flat screw driver to hold the brush spring down. Carefully fold down the brush holder tab on top of the brush spring or flat contact. Be sure that the spring or flat contact is flat against the brush holder tab and not folded over or part way out.
10. Check the fold of the brush holder tab. If the fold is cracked, the tool must be sent to STANMECH to have the brush holders changed.
11. Reassemble the tool, plug it in and turn it on. Run it cold for a minute to confirm that the motor operates properly. The motor may run rough at first – this is normal until the brushes are worn in.

Extra Tips when Changing Brushes

• If the motor was sputtering or stopping but the brushes are almost new and worn so that the angled portion at the end is almost worn down to the straight portion, it is likely that the last time the brushes were changed the brush holders were not properly cleaned. Clean the brush holders.
• Do not let the brush wear down to the spring or the stop; this risks damage to the element, mica tube and, in the case of brushes without stops, the motor.  Note how long the previous pair took to wear down and use that information to estimate the next time the brushes should be checked.