Cummins/Onan 6.3 NHEL / 6.5 NH — Generator Brush Replacement

Maintenance · Brush block and slip rings

For the Cummins/Onan 6.3 NHEL / 6.5 NH, from the Cummins/Onan service manual.

Applies to: Cummins/Onan NHEL

Procedure

1. Disconnect the negative (-) battery cable at the battery terminal.
2. Remove the air cleaner cover and air cleaner filter element.
3. Disconnect the B+ (outboard) and B- (inboard) lead wires from the brush block terminals.
4. Remove the brush block mounting screws and lift out the brush block.
5. Remove brushes and brush springs from holder and replace with new parts.
6. Pull each brush outward and insert a stiff wire through the small holes in the base of the holder to hold brushes off the slip rings.
7. Install brush block in housing but do not tighten mounting screws.
8. Remove holding wire; adjust brush block so brushes are centered on the slip rings and tighten mounting screws.
9. Connect the B+ lead to outboard terminal and B- lead to inboard terminal.
10. Install brush block cover and tighten mounting screws.
11. Install air filter element and air cleaner cover.
12. Connect negative (-) battery cable to battery terminal.

Full service-parts list: Cummins/Onan NHEL →

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.

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