The injector nozzle bore in the cylinder head passes through the cylinder head water jacket. To prevent coolant from contacting the injector nozzle, a steel tube is installed into the injector bore. The tube has a ring seal at the top to create a watertight and airtight joint.
To determine if injector tube replacement is required. See Figure 25743 .
Injector Nozzle Tube Replacement Flowchart
Note: The injector nozzle tube should be replaced whenever the engine is overhauled.
When removing an injector nozzle tube, use injector tube removal tool set J 41575.
Remove the injector nozzle tube and O-ring as follows:
Thoroughly clean the injector tube hole in the cylinder head to remove any dirt, burrs, or foreign material that may prevent the new injector nozzle tube from sealing properly.
Install the injector nozzle tube as follows:
Note: Whenever an injector tube is removed for any reason, it should be replaced.
Do not lubricate the outside of the injector nozzle tube or the inside of the cylinder head injector nozzle tube bore. Lubricant may cause the tube to loosen, resulting in lube oil dilution that may lead to engine damage.