The Cummins/Onan B5.9 Series is a 5.9 L 6-cylinder turbocharged and after-cooled engine rated at 2100 rpm, producing up to 91 kW. It powers generator sets from Cummins/Onan, including the 6BTAA5.9-G5 CoolPac, 6BTAA5.9-G7, B5.9 and B5.9 engine. It holds 14.2 L (3.8 gal) of oil and 15.1 L (4.0 gal) of coolant.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Cummins Filtration AF26125 | | — | | |
| Fuel filter | Recommended fuel filter - primary, secondary | | — | | |
| Oil filter | Recommended lube oil filter | | — | | |
| Battery | 12V-DC | | 12V-DC | | Amazon Amazon eBay eBay $69.95 FridayParts $11.85 |
| Belt | Battery cable size - minimum of 2/0 AWG and maximum cable length not to exceed 6 ft. (1.5 m) | | — | | |
| Coolant filter | N/A | | — | | |
| Oil | Oil capacity of pan (high - low) | 15.0 qt | — | | |
| Spark plug | | | — | | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Procedures
1Connect the INLINE™5 Datalink Adapter to a Personal Computer installation
⚠ A fully populated USB cable, Part Number 4918419, or DB9F-DB9M serial cable, Part Number 4918418, must be used.
- Connect the DB9F-DB9M serial cable, Part Number 4918418, or USB cable, Part Number 4918419, to the computer.
- Connect the other end of that cable to the INLINE™5 datalink adapter, Part Number 3165033.
- Supply +8 VDC to +50 VDC at 250mA through the OEM connector or a separate power source.
- Connect the appropriate datalink cable to the INLINE™5 datalink adapter, Part Number 3165033.
- Connect the other end of the datalink cable to the vehicle cab or engine compartment datalink connector.
- Launch the electronic service tool application software.
Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.
Common questions
What is the oil capacity of the Cummins/Onan B5.9 Series?
The Cummins/Onan B5.9 Series engine has an oil capacity of 14.2 liters.
What is the displacement of the Cummins/Onan B5.9 Series?
The Cummins/Onan B5.9 Series has a displacement of 5.9 liters with 6 cylinders.
Which generators use the Cummins/Onan B5.9 Series engine?
The Cummins/Onan B5.9 Series powers 10 generator set(s), including Cummins/Onan 6BTAA5.9-G5 CoolPac, Cummins/Onan 6BTAA5.9-G7, Cummins/Onan B5.9, Cummins/Onan B5.9 engine, Cummins/Onan B5.9 series.