Cummins/Onan — Brush Inspection/Replacement
Repair & overhaul · Generator brushes
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKA
Before you start
- Stop the generator set and disconnect battery cables (negative first) before inspecting.
Procedure
- Remove the access cover for the brush assembly.
- Check brush wear with a piece of wire marked 1 inch (25 mm) from one end.
- Replace the brush and spring if the wire enters the brush holder 1 inch or more.
- Remove the brush holder: disconnect two leads and two mounting screws.
- Install new brushes and springs in the holder.
- Insert a wire through the holder to retain brushes during assembly.
- Install the brush holder and tighten the mounting screws.
- Pull out the retaining wire, then connect F1 and F2 leads.
Tools required
- Wire marked at 1 inch (25 mm) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Replace brush if wire enters holder 1 inch (25 mm) or more
- Connect F1 lead to inner brush terminal; F2 lead to outer brush terminal
Full service-parts list: Cummins/Onan HDKA →
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.