Cummins/Onan — Check/Clean Generator-Alternator Brushes and Commutator
Maintenance · Generator/Alternator
From a Cummins/Onan service manual covering: V12 Series, V6-140, V6-200, V6-VAL, V6-VIM, V8-185, V8-265, V8-350, V8-VALE, V8-VINE, VT12, VT8-430. Check it applies to your exact model before use.
Applies to: Cummins/Onan V12 Series
Before you start
- Never use emery cloth.
Procedure
- Clean dirty commutators with No. 00 sandpaper; never with emery cloth.
- Replace worn brushes.
- If brushes wear rapidly, check for incorrect brush spring tension or high mica on commutator.
- Check output and action of an ammeter indicator after brush replacement.
- Take unit to electric service station for shorts and incorrect polarization.
Tools required
- No. 00 sandpaper Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan V12 Series →
Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.