Usage:
3406E (5EK) Truck Engines
Reference: Service Manual Module, Disassembly and Assembly 3406E Diesel Truck Engine, SENR6421-01, Page 8, "Electronic Unit Injectors".
This information supersedes the information in the Reference. Make note of this information in the Reference.
The preferred practices for removing and installing electronic unit injectors follow:
Loosen the air bleed screw on the fuel block to relieve fuel system pressure and minimize the amount of fuel draining into the combustion chamber. After removing the valve cover, loosen the two nuts on the Electronic Unit Injector (EUI) cap. Remove the wires from the compression brake solenoid and remove the compression brake/rocker shaft assembly as a unit.
Loosen the injector hold down bolt and use a 5F-4764 Pry Bar to pry under the injector hold down clamp. Do NOT pry on the injector body. The clamp is easily accessible and the EUI body can be damaged as indicated by several field returns. The entire assembly can then be removed as a unit. Make sure the small bottom O-ring is still on the injector tip. If the O-ring is accidentally left in the cylinder head, it can cause the injector clamping load to be incorrect. This can result in a loose EUI. Inspect the tapered injector seat in the cylinder head for carbon build-up. Use the tapered brush to clean up the seat. Use the small diameter brush for cleaning up the bottom deck through hole. These brushes are found in the 9U-7530 Engine Tool Kit.
Number each injector if more than one injector is removed from the head. The injector code on the tappet must agree with the code on the Electronic Control Analyzer Programmer (ECAP) screen. If a new injector is installed, write down the new injector code before assembly.
Inspect the O-rings for cuts or abrasion prior to assembly. Lubricate the O-rings with a petroleum based product such as clean engine oil. A water based product such as STP can cause rusting of the injector cone.
Use care to not damage the injector tip. Scotchbrite can be used to carefully clean the tip and cone seat areas prior to installation. Assemble the clamp, spacer, bolt, and injector together as an assembly when installing the injector back into the head. Tighten the hold down bolt to a torque of 56 ± 9 N·m (41 ± 7 lb ft). Install the wiring harness and terminal cap. Tighten the nuts to a torque of 1.75 ± .25 N·m (15 ± 2 lb in). Then proceed with the assembly of the rest of the engine.