Cummins/Onan B43 / B48 — Crankcase Breather Service
Maintenance
For the Cummins/Onan B43 / B48, from the Cummins/Onan service manual.
Applies to: Cummins/Onan B48
Before you start
- Most parts cleaning solvents are flammable and can cause severe personal injury or death if used improperly.
Procedure
- Remove the breather tube from the valve cover.
- Remove the valve cover, pack, spring, washer, reed valve, and breather baffle.
- Discard gasket and clean all parts in parts cleaning solvent.
- Check that the reed valve is flat with no sign of a crease.
- Assemble using a new gasket.
- Do not overtighten valve cover capscrew.
Full service-parts list: Cummins/Onan B48 →
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.