Cummins/Onan — Remove and Install Injectors (Flanged)
Repair & overhaul
From a Cummins/Onan service manual covering: V12 Series, V6-140, V6-200, V6-VAL, V6-VIM, V8-185, V8-265, V8-350, V8-VALE, V8-VINE, VT12, VT8-430. Check it applies to your exact model before use.
Applies to: Cummins/Onan V12 Series
Before you start
- Do not bruise injector tip.
- Do not turn injector upside down; plunger assembly can fall from injector body and ruin plunger.
- Never use a screwdriver or metal tool to clean injector seat.
Procedure
- Remove rocker cover.
- Disconnect fuel inlet and drain manifolds from injector connections.
- Remove fuel inlet and drain connections from injector body.
- Loosen injector adjusting screw, locknut and back off screw until push tube can be disengaged.
- Disengage push tube and tip rocker lever back.
- Remove hold-down capscrews and lift injector.
- Installation: clean injector seat with a clean cloth wrapped around a wooden stick.
- Assemble injectors in position.
- Start, but do not tighten, injector hold-down capscrews.
- Screw in inlet and drain connections about three turns to align injectors.
- Oil hold-down capscrews and tighten to Table VIII value.
- Tighten inlet and drain connections to 20/25 foot-pounds.
- Position injector rocker lever on injector push tube.
- Adjust injectors and valves.
Tools required
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Hold-down capscrews per Table VIII
- Inlet/drain connections 20/25 foot-pounds
Full service-parts list: Cummins/Onan V12 Series →
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.