Duramax (LB7) Injector Removal and Installation
Start by removing the lower valve cover. Carefully watch for debris as fuel injector lines are removed. It is possible for debris to fall into these openings/fittings. Remove any debris that enters these openings. Verify which side of the banjo washers have the larger outer diameter.
Remove the fuel injector return lines from the injectors. Now remove the bolt from the fuel injector bracket.
Using the (J44639) Connect it to the injector retaining bracket. Install a wrench to the (J44639) to leverage/pry the injector from the head. Once the injector is free remove with your hand. Inspect the injector to verify that the copper compression washer was removed also. Remove washer from sleeve if it did not come out with the injector.
Now inspect the injector and sleeves for any possible damage. If the sleeve came out with the injector or shifted during removal you will need to replace the sleeve and o ring for the sleeve. You will now need to clean the sleeves. This will remove any carbon build up inside of the sleeves. Using the radial brass brush (EN-47909-2) and handle (EN-47909-1) clean the interior of the sleeves of any carbon deposits. Use air to remove any debris that appears in injector sleeve. Avoid excessive cleaning solvents entering the cylinder. A slightly dampened cotton swab (EN-47909-20) should be used to wipe interior of injector sleeve. Verify that all debris has been removed from the sleeve before installing injectors.
***DO NOT USE ENGINE CRANKING TO REMOVE EXCESSIVE SOLVENTS FROM THE CYLINDER, THIS CAN CAUSE THE SLEEVE TO MOVE AND WILL RESULT IN COOLANT ENTERING THE CYLINDER***
It is now time to install your injectors. Lubricate the injector o ring and verify that the copper washer is in place on the injector. Using the injector bracket install the fuel injector. Install the injector bracket bolt. Tighten the bolt to 50Nm (37 lb ft). You will not need to install the return pipe assembly. Following this step you will need to install the fuel injector return line to injector eye bolts and washers. Make note to lubricate the washers prior to installation. Tighten the fuel injector line to injector eye bolts to 16Nm (12 lb ft). You will now need to tighten the fuel injector return line to the cylinder head eye bolts 17Nm (12 lb ft).
Install the lower valve cover to complete injector install.