Injector Replacement Best Practices

[Dustin_360]

Hey Guys- What are best practices for replacing injectors while working on these LML’s or other common rail trucks?

I’m going to pull injectors on my 15 LML and wondering if anyone has any advice they would like to share. Seems like the biggest thing is keeping stuff clean clean clean (don’t introduce contamination)! How paranoid do I need to be? Here is what I have so far.

-Clean fittings with airgun, degrease, airgun again before starting.
-Cover the rail ports with vinyl caps while the injectors are sent out.
-Any recommendations for lint free cloths? Just disposable shop paper towels?
-Keep pulled lines bagged up to prevent contamination
-Bleed fuel system a few gallons through Schrader valve before initial startup

Any other tips? I’ve been wrenching my whole life but first time doing diesel injectors. Will I need an injector puling tool? Looks like you can flip the hold down over and tap with a hammer to remove. Truck has 55k miles.

Injectors are being sent out for 45% over. Also doing a 10mm CP3 conversion and installing a stealth turbo while I’m in there.

 

[monster50iii]

Get a 12g shotgun cleaning kit from Amazon, spray them all down with aerokroil for a week or two before you pull them, otherwise I don't think you can be too anal

 

[Dustin_360]

Get a 12g shotgun cleaning kit from Amazon, spray them all down with aerokroil for a week or two before you pull them, otherwise I don't think you can be too anal

That's a good idea with the penetrating oil. Do you use the 12 gauge brush to clean the injector bores in the head after you pull the injector?

 

[monster50iii]

Yes, I also use compressed air to blow the cryd out afterwards. I soaked mine for a few weeks, and they all came out super easy. Truck had 220k miles and is a northern salt truck.

 

[Josh154]

Getting ready to do mine on lml. I did them on my lmm. Are the return lines a bitch on lml like lmm? I kept breaking the plastic T’s and had troubles with some sealing.

 

[LBZ]

I’ve never ran into issues breaking the t’s. You just need to be a man with a slow hand and be gentle.

I think the op has most of the bases covered. I find if you give them a bit of a twist such as you can it helps free them up and they come out easier.

 

[Dustin_360]

About a half way through with the job, Injectors have been removed and sent to S&S for rework. A few things I have learned for other people wanting to attempt this...

In addition to what I mentioned above...

-Spray a liquid grease that solidifies on to the top of each nut before removing, give it enough time to setup. This is mentioned in a procedure somewhere to use AC Delco 12346241. This will help hold debris from falling into the injector during line removal.
- Use cleanroom style gun tip foam swabs to clean around the fuel rail port injector port or anywhere you don't want particles or lint.
-If you get minor debris in somewhere you can use a shop vac with a cut drinking straw taped to the end to extract. I had two injectors that got a bit of debris in them from the seat. When removed I vacuumed them upside down to minimize contamination. I believe S&S is gong to clean them as well before rework. This might be a gamble otherwise... guess it depends how much contamination you got in there and effectively you were able to remove/flush.
-Unless your injectors are seized in the head on you can probably remove them by hand and don't need a removal tool. Most of them crack loose when breaking the line connection at the injector seat. If you need a little extra help can just flip over the hold down to give a little extra coaxing. I did spray the bore with penetrant fluid a day or two before starting.

The gun cleaning kit worked quite well to clean the holes in the head. I used the soft swab and soft wire brush, I think it's brass or a softer metal and attached the cleaning heads to 6 or so inches of flexible plastic water line to get all the way in. After cleaning the holes I needed to detail the areas where the copper seat goes with the little foam Q tips. These things are great since they don't leave any lint or cotton particles.


I have a question about tightening the injector hard lines... Can I use a little oil on the seat and threads before tightening? I'm wondering if oil on the seat is ok but maybe no oil on the threads. Then come back when the job is complete an treat with an anticorrosion spray to prevent moisture damage to areas not sealed.