I decided to pull the injectors out before ordering the new set. Then I'm ready to immediately return for the core charge once I receive the new ones. Obviously the truck isn't going anywhere while I wait, but that's OK.



So, I started pulling injectors... I used the round end of an air chisel to fit in the hole of the hold down bracket and moved the injector side-to-side and gently pried under the bracket to lift. Well, the first three injectors came right out.. along with the cups! I set them on the bench and needed two flat blade screwdrivers to pry the cup off the injector. I found the o-rings on the injectors had rolled out of the grooves and the entire body of the injector and inside the cup was caked with carbon. It seems all that crud cemented the cup to the injector, which seems to explain why the assembly came out rather than just the injector.



I thought as part of the install, that red loctite was supposed to be coated around the bottom of the cup where it seats in the head, but the cups were absolutely clean on the outside when I pulled them out. I was surprised, because the last injector replacement was done by GM under the original warranty. Am I right about using the loctite on the bottom of the cup?



I need some advice on the best way to re-install the cups and injectors. Right now I'm thinking that I need to install the injectors into the cups (on the bench), then coat the cup with loctite at the bottom and re-install the assembly into the head, using the hold-down bracket to seat the assembly. If I torque the injector into place that should hold the cup properly while the loctite dries.


Sound right or is there abetter way? Thanks again for all the good advice!