Cummins/Onan — Replacing Brushes
Maintenance · Generator brushes
From a Cummins/Onan owner's manual — check it applies to your exact model before use.
Browse Cummins/Onan generators & specs →
Before you start
- Weak spring tension leads to excessive brush sparking and pitting.
Procedure
- Install new brushes when the old brush top is below the midpoint of the guide.
- Do not continue to use brushes worn too short.
- Apply only a moderate load until new brushes have been run in.
- See that brushes ride freely in their guides and spring tension is uniform.
- Set tension to 30 oz. for commutator springs and 16 oz. for collector ring springs.
Specs & values
- Commutator brush spring tension 30 oz.
- Collector ring brush spring tension 16 oz.
Source: Cummins/Onan owner's 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.