Cummins/Onan — Turbocharger Wastegate Capsule (3-03) Checking
Testing & diagnosis
From a Cummins/Onan service manual covering: 4B3.9, 4BT 3.9, 4BTA 3.9, 6B5.9, 6BT 5.9, 6BTA5.9, B3.9, B5.9. Check it applies to your exact model before use.
Applies to: Cummins/Onan 4B3.9, Cummins/Onan 6BTA5.9
Procedure
- Visually inspect the wastegate actuator hose for cracks or holes. Replace if damaged.
- Visually inspect the wastegate mounting bracket, actuator rod, and lever for damage.
- A bent bracket, rod, or lever must be replaced. Refer to Procedure 3-05.
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.