Well-Known Member
Aug 27, 2013
In doing my Intake Manifold swap I also did some other things that made sense to do while I was in there. This write-up will focus on the removal of the fuel injectors, which also is the same if you are just replacing the seals(o-rings), the process should be the same across motors and years, but the P/Ns and torque specs will be specific to 2004-2007c.

Since I was swapping injectors over to the new intake I was able to do this with the fuel rail removed from the intake and out of the engine bay, but it can be easily done with out removing.

Suggested Parts: GM p/n 12587147 - Upper & Lower O-ring set (Includes enough for all 8), 12570620 - retainers (I reused mine w/no issues)

Tools you'll need: 1/4" or 3/8" socket wrench, 3" extension, 8mm socket, 10mm socket, prybar, flat head screwdriver, angled pick, inch LB torque wrench, blue loctite

1.) Start the truck, then with it running pull the fuse for the fuel pump (under hood) and let the truck run until it dies. Reinstall the fuse after it dies

2.) Remove engine cover using 8mm socket

3.) Go through and unplug your injectors (either the one you are replacing or all if replacing o-rings). They are attached with a gray slide clip that you pull up on and then press in a tab and pull up. Its fairly self explanatory if you look at them. I found it easier to pull the entire slide piece up and off, then press in, than to leave it on.

They look like this:

4.) Unscrew the cap on the fuel pressure relief valve and depress the stem with a flat head screwdriver with a rag underneath to release any remaining pressure in the rails

5.) Take your 10mm socket and unbolt the four(two per side) bolts holding the rail to the intake

6.) Take your pry bar and wedge it under the fuel rail pulling up gently to pull the bottom of the injectors out of each side of the intake manifold. *If just replacing a single injector, you should only have to do the side you are working on.*

7.) Take your pick or flat head and pry the retainer the holds the injector to the rail off, discard if replacing, set aside if reusing.

I found the angled pick to be the easiest way to pull them off, but a small flat head would work just as well if doing while in the truck:

8. Remove your injector (one or all 8) by twisting and pulling down(in my case up). You may want to put a rag underneath to catch any residual fuel.

9.) Next wipe the injector down, cleaning it of any grease,dirt,ect.

10.) Take your pick and remove the old o-rings, wiping down the surface underneath as well

11.) Reinstall the new o-rings (fat on top, skinny on bottom)

12.) Push the top of the injector back into the fuel rail. *I found it easier to put a very light coat of clean oil on them before pressing back in*

13.) Push the retainer back into place holding the injector to the rail, its a little bit goofy but it'll snap right on once its lined up right

14.) Repeat x8

15.) Push the fuel rail back down into the intake manifold lining the bottom of the injectors up with the holes.

16.) Reinstall the four 10mm bolts, using blue loctite on the threads and torque to 89in-lbs

17.) Reinstall engine cover

18.) Turn key to run a few times to re-pressurize the fuel system, then turn the tuck on.

And thats it you're done
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