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LB7 injector replacement with pics.

122K views 251 replies 106 participants last post by  shakerattlenrol 
#1 ·
What follows is how we replaced the injectors on my 03 LB7.
I AM NOT A GM TECH, please follow these at your own risk. I am a DIY'er, sharing our experience, with this task.
The parts we used;
97729095* Injector Kit, Dir Fuel (Incls:Injector,Gasket,Seal) 8


97188896 Gasket, Valve Rocker Arm Cover
(Reusable Gasket) As Req'd


97228933 Gasket, F/Injr Fuel Return Pipe 8
97600925 Gasket, F/Injr Fuel Return Pipe 2


88901148 (CN) Sealant As Req’d


97300793 Seal, T-Stat (2) required


Job specific, tools used;
The first one is a "heel bar" that we used to actually pull the injectors loose from the bores.


Next the 5mm allen ball socket (with universal) and the ball tip allen wrenches;


Then comes the fuel line release tools. The first one I already had, from doing fuel pump replacement on my gassers.



That one worked on the return line, but was not large enough for the feed line, for that I had to by this set, just to get the 1/2" one;




Next, how we protected the paint on the front of the truck. Three shipping blankets from harbor frieght, were zip tied around he nose of the truck. I think they were six bucks each.





OK, now on to the actual job.
1. Disconnect both batteries.
2. Drain coolant. No pics of those two steps, but a (5) gallon pail will slide under the pas front of truck, then loosen the rad. drain plug, until the coolant begins to escape. Then just be patient, if you rush it, like I did, there will be a mees on the floor.
3. Remove air intake and box. Disconnect the MAF sensor, loosen the clamp on the turbo inlet, then lift the assembly up on the hose end, while sliding the box toward the driver side of the truck.

4. Remove intercooler pipe from intake down to intercooler and the heater core, hard line;




5. Remove the FICM;


6. Then the FICM bracket;


7. Remove the fuel filter assembly;



8. Remove the 8mm nut, and glow plug wire;



9. This shold give a clear look at the upper valve cover, in this pic, the clips are not on, sorry;

here is a shot of the clips, on the driver side, the bolts are 8mm heads;


10. Remove those 8mm screws, then remove the 19mm fittings that hold the high pressure lines to the common rail, and the injectors themselves;
once agian, I missed getting a good pic of this step, but here one from the drivers side;

There is allot of talk about corrosion on the high pressure lines, we did not have an issue with that;




11. Next, remove the 5mm screws that hold the upper cover. The upper cover is "glued" on with the GM sealant. To remove the cover, there are two "pry points" cast into the bottom of the cover. Use those points to lift the cover, then slide something under it, and finish gently lifting it up. The following pics were taken on the workbench to give a better idea of what they look like.





12. Once you remove the upper cover, you will see the wiring harnesses, that run the injectors. There are (2) 10mm bolts that hold the harnesses to the head, and each injector has (2) 7mm nuts that hold the wires to the injector. Those 7mm nuts are "captured in the wire ends, they stay with the wires.



13. With the wires out of the way, you can remove a bunch more 5mm screws, to get the lower cover off;

The lower cover has alittle bit different retention hardware. There are spacers that keep the gasket for the lower cover from being smashed;


14. With the lower cover off, the next thing to remove is the fuel return line;



15. This is where the seals for the return lines come in, clean the line up, remove the old seals, and replace them with the new ones. Then set aside, until reassembly;



16. Remove the 8mm cap (allen head) screw that hold the injector clamp, then slide a pry bar under the clamp and "pop" the injector up out of the bore. Here again is an area where I did not take good pics, I will post what I have, and hopefully it will make some sense;


This is the pass side ones, out on the bench;



17. Clean the bores, install the new squirters in the bores, and reverse the steps listed above.

18. The driver side is the same, only with more "stuff" in the way. First remove the inner cooler tube;


19. Then remove the upper rad hose, notice the small rubber hose that runs to the turbo, remove that, the (4) 12mm screws that hold the T-stat housing on, and the (2) 12mm bolts, that hold the hard line on the left upper valve cover.

One of those bolts is hidden by the large bale connector;


20. Remove the (3) 12mm bolts that hold the large bale bracket to the driver side upper cover, here again, no good pics.

21. Use the fuel line wrenches to release the fuel lines. First remove the spring clips, then the lines themselves;



22. The above pic shows the Glow Plug Module. We completely removed that from the truck, next time, I will disconnect the wires, to the point where it can just be moved out of the way;


23. At this point, you should be able to remove the high pressure lines (clips first);



24. From this point, the driver side is just like the passenger side. Just without as much room to work. Don't forget about the glow plug wire;


25. One thing to take note of upon reassembly, is to seal the top of the high pressure line fitting. On the injector end. This keeps dirt and debris from building up in that fitting, and dumping inside of the head, next time you break it loose;


Thats about it, obviously reverse the above steps to reassemble. Prime the fuel system, fill the radiator, remove the bleed screw to get some air out;


Reconnect the batteries,andfire it up.

One thing I did not mention was the injector cups, we were lucky, and none of mine came out. But I made sure my dealer had some in stock, and I have Loctite in hand.

Hope this helps, anyone who has done it, and wants to add to this thread, please feel free.
 
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#2 ·
Did you have to remove anything from the front of the motor like AC compressor or alternator brackets ??

How much time did it take and about how much were all the parts ?

Thx for the pics

DD

.
 
#3 ·
Did you have to remove anything from the front of the motor like AC compressor or alternator brackets ?? Yes I did remove the AC Compressor, and Alt, but after I had it all apart, I realized that I could have done the job without removing them. Next time I won't.

How much time did it take and about how much were all the parts ?
Parts;http://www.dieselplace.com/forum/showthread.php?t=273043
Green Thunder sent lower cover gaskets, return line seals, and sealant in the box. I have less than 1K into the job, $48.00 for a new WIF sensor. I did not time the job, but 15 or 16 hours sounds about right.
Thx for the pics

DD

.
Here's a link to my photobucket account if anyone wants to see the rst of the pics we took.
http://s6.photobucket.com/albums/y248/atkxr600/
 
#8 ·
Great write up, I vote make it a sticky.
 
#9 ·
Very nice write up. Way to tackle this job yourself. It is not that bad just a have to remove a bunch of crap to get to the injectors huh? You were lucky with the high pressure lines also, all of them I have done have all had corrosion.
 
#14 ·
Excellent job!!!
 
#15 ·
GOOD JOB!! I will be saving this thread since my warranty is almost over. Thanks for the pics.
 
#16 ·
What was the total cost?

Also THANK YOU!!!! This is exactly what folks were looking for. and as stated, anyone who has done this, and has something to add or pictures to add, they would be helpful!

Not to step on your thread, but this is what I was looking for back in January when I started the other thread.

Excellent JOB!
 
#17 ·
Not to step on your thread, but this is what I was looking for back in January when I started the other thread.
Excellent JOB!
Do not worry about stepping on this, I tried to update your other one, as I have it saved, but it was closed:banghead::banghead::banghead::banghead::banghead: . Then I went back later and it was open:eek::eek::eek::eek:. Or I was seeing something wrong???.

So I started this one instead. If you notice, some of my fonts are a little wacky, that's because I was coping and pasting from your old one:D:D:D:D:D.

Anyhow, I feel like all of us LB7 guys are in this together, I put this up, as a tool for anyone. And anyone who can add to it, get er done. I'm open to criticism, as long as it constructive.

We all need the easiest, least expensive way to keep these bad boys on the road. If we put our heads together, we stand a better chance:cool::cool::cool:.
 
#18 ·
Thanks for posting the pics and directions. When I have to change mine I'll definitely be using this thread for help.
 
#20 ·
Yeah, funny thing is, the truck spent it's life in Wisconsin????????
Pretty sure they use salt over there.
 
#21 ·
I Am About To Tackle This Same Job And Without This Post I Would Have Been Shooting In The Dark. I Really Appreciate The Time Taken To Post This To Help Others With The Same Problem.
 
#32 ·
great write up and it looks like I will be using it since my dealer is telling me the injectors are not bad but I am having the bad smoke and smell at idle in gear. I am going to try to fight them but don't think I will win. i only have 112,000 mile on my 04 on second set of injectors but getting embarrased at smoke.
 
#24 ·
Also like to add, you can let some air out of your front tires and lower her down a bit.
 
#25 ·
Injectors

Sweet write up! I appreciate the time and effort you put out hoping to save us time, effort and mistakes when we have to do this swap. My 02 is in the shop right now getting all the injectors replaced. I figured since it was on my 02 I'd be doing this myself soon but maybe I won't need your post until the next 100k miles comes around!

I'll print this out and save it.

Thanks again.
nvrstuk
 
#26 ·
hey Z71
l was wondering if you looked at the ( l think they are called precups) that the injectors set into. l heard some rust. just asking
 
#28 ·
No I did not look at the cups. I made sure that my dealer had them in stock, just in case one came loose. But none did. The parts guy at my local dealer, has been a friend since HS. He takes care of me.
 
#29 ·
thanks guys
 
#30 ·
Good job! Most of the time the cups don't come out unless someone has installed injectors before and they didnt get everything cleaned up and the copper washers didn't seal upon installation and combustion made its way up beside the injector and carboned everything up. Good write up!

Spencer
 
#31 ·
Thanks so much for posting this! I'm likely going to run out of time before I run out of mileage (at 119k now) and I don't currently have return rates large enough for GM to take action. I do have blue smoke at idle when hot so I'm considering possibly doing this myself if GM refuses to take action. Excellent write up! I'm pretty sure my lines are corroded but as long as they aren't damaged when they're removed, why are people replacing them? Besides them "possibly" failing down the road, it sounds like a large expense for preventative maintenance.

FYI, if you guys sprayed the lines and any other items that could become corroded with LPS3, you should have NO issues with corrosion in the future. My father has been using that stuff for years with great results, I've started using it also. It leaves a waxy coating that doesn't drip off or make a mess, but protects against salt and rust.
 
#33 ·
I'm pretty sure my lines are corroded but as long as they aren't damaged when they're removed, why are people replacing them? Besides them "possibly" failing down the road, it sounds like a large expense for preventative maintenance.
I obviously can not speak for everyone, but here are my thougths on the lines.

The lines were designed to "crush" or "deform" as they are torqued onto the injector, and common rail. This "crush" or "deformation" is a large part of how they seal. The pressure through these lines can reach 23,000 psi, so the "seal" is pretty critical. This "crush" really only happens one time, in the life of that metal, and that one time, is the first time, they are torqued down.

Anytime the lines are re-installed, the "crush" factor is greatly reduced. Therefore, the line may not seal. Keep in mind, that seal, takes place inside of the valve cover (internal to the engine), if it leaks, the first place you will see it, is in the oil(the crankcase will fill with diesel).
http://www.dieselplace.com/forum/showthread.php?t=275565

I DID NOT replace my lines, I took note, of the oil level before the install, and kept a close eye on it afterward, to make sure it wasn't rising. It looks like mine sealed up OK. The lines were like $98.00 each, my cost at the dealer. Tolliwacker scored some on eBay, but I did not find any there.

Long reply, I know, just keep in mind, corrosion is not the only reason for changing the lines.
 
#34 · (Edited)
I replaced all my lines and did do one reinstall on the passenger side and the truck never leaked.

I also think, after judging by the conditions of lines I took off, the tech that replaced the set under warranty was a monkey. Every line had some rounding...which I believe indicates they were probably not torqued properly.

So hopefully the new set I installed lasts since I know they where torqued properly.

BTW: I got my lines for about $66 per line online...still expensive but I did not want to deal with any issues
 
#35 ·
Well I am noticing some smoke at idle................Sooooooo It appears I may be a candidate of injectors in the very near future. I am at 184,000 so I will attempt to get the general to replace them, but I am not gonna worry to much about it till it gets worse. I have until Oct 2010 for time on the 7 year/200K special policy so I have to be careful about the milage.

After 152,000 miles on these injectors, I may be nearing the end for this set!
We will see........................................
 
#38 ·
I have stinky BLUE smoke only at idle when warm. ZERO smoke when cold, even immediately after startup. The idle is SMOOTH, not rough at all, power seems to be fine (though I am running DSP5 with a few pretty hot tunes). MPG is around 20 on the highway @65mph with an econ tune. So far I'm not making oil.....
 
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