Cummins/Onan — Fuel Pump - Replacement
Repair & overhaul · fuel system
From a Cummins/Onan owner's manual covering: 6C8.3, 6CT 8.3, 6CTA8.3. Check it applies to your exact model before use.
Applies to: Cummins/Onan 6CTA8.3, Cummins/Onan C Series, Cummins/Onan 6CT8.3 engine
Before you start
- Do not exceed the torque value given for the retaining nut; this is not the final torque value
Procedure
- Clean debris; remove fuel lines, control linkage and fuel shutoff solenoid.
- Locate TDC cylinder 1; push TDC pin into camshaft gear hole.
- Remove gear cover access cap; remove nut and washer from pump shaft.
- Pull the drive gear loose from the shaft with a 75 mm T-bar puller.
- Remove the four mounting nuts and remove the fuel pump.
- Align pump timing pin; install pump with cylinder 1 at TDC.
- Install mounting nuts 43 Nm [32 ft-lb]; retaining nut 10 to 15 Nm [7 to 11 ft-lb].
- Disengage timing pin; tighten drive nut PES6A 93 Nm, PES6MW 105 Nm.
Tools required
- 22 mm and 27 mm sockets Amazon
- 75 mm T-bar puller Amazon
- 15 mm and 24 mm wrenches Amazon
- Torque wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Mounting nuts 43 Nm [32 ft-lb]
- Retaining nut 10 to 15 Nm [7 to 11 ft-lb]
- Drive nut PES6A 93 Nm [68 ft-lb]; PES6MW 105 Nm [77 ft-lb]
Full service-parts list: Cummins/Onan C Series →
Source: Cummins/Onan owner's 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.