Detroit Diesel — Injector Unit Pump Removal
Repair & overhaul
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- PERSONAL INJURY: wear a face shield or goggles to avoid injury from sudden release of a high-pressure hose connection.
- EYE INJURY: wear adequate eye protection when working with components under spring tension.
- NOTICE: Do not pry up on the body of the pump; this will damage it.
Procedure
- Remove the engine trim cover.
- Unscrew the fuel filter cap.
- Disconnect the engine wiring harness from the injector unit pump.
- Remove the high-pressure fuel injector line (refer to 2.3.1).
- Disconnect the fuel line at the fuel gallery inlet, catching any fuel.
- Drain fuel from the engine through the fuel gallery outlet on the return lines.
- Remove the end cover from the lower right of the flywheel housing and attach engine barring tool J-46392.
- Loosen the injector unit pump mounting bolts about 6 mm (1/4 inch), but do not remove.
- Rotate the crankshaft with J-46392 until the cam pushes the unit pump upwards.
- Release a locked-up pump using the blade of a small screwdriver under the mounting bolt flange.
- Remove both mounting bolts and pull the unit pump out of the cylinder block.
- Check the pump for fuel leakage at the solenoid and for wear or damage.
- Remove and discard the two O-rings on the unit pump shaft.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Loosen mounting bolts about 6 mm (1/4 inch)
Source: Detroit Diesel 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.