Cummins/Onan — Servicing Brush Block
Maintenance
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKB
Before you start
- Disconnect negative battery cable before removing access panel.
Procedure
- Remove left access panel for access to brush block.
- Disconnect field leads; remove mounting screw; withdraw brush block.
- Replace assembly if either brush is shorter than 7/16 inch (11 mm) or damaged.
- Reconnect field leads: F- (black) outside terminal, F+ (red) inside terminal.
Tools required
- Screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Brush minimum length 7/16 inch (11 mm)
Full service-parts list: Cummins/Onan HDKB →
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.