Duramax Injectors

[HEEP]

Anyone here changed out a set of LB7 Duramax injectors? Everything I have read states it is just time consuming, not really that hard.

[Brewtal66]

Originally Posted by HEEP

Anyone here changed out a set of LB7 Duramax injectors? Everything I have read states it is just time consuming, not really that hard.

Just asked my buddy about this...he said it took him 13 hours, and cost him about $2300 in parts. And he's about due to do it again.

[camcojb]

I swapped them out on my LMM, not that big of a deal other than getting to all of them.

[BlueSS454]

Originally Posted by Brewtal66

Just asked my buddy about this...he said it took him 13 hours, and cost him about $2300 in parts. And he's about due to do it again.

That would be me . And yes it was a 13 hour job.

It's not overly hard, but is very time consuming. You have to drain the coolant, remove the turbo pipes that go over top of the valve covers, disconnect the wire harness and flip it out of the way then you can access the valve cover bolts. Then you need to remove the fuel filter & pump assembly, disconnect the main fuel lines, leads off the glow plugs, remove the upper radiator hose with the thermostat housing, air filter box and anything else that's in the way.
Next you can remove the individual feed lines to the injectors. You need a crows foot line socket for this.
You will need some metric ball ended hex keys and sockets to remove most of the valve cover bolts. They are not really tight so they should come right out. The hardest part is getting the upper valve cover off. GM uses this sealant that is about as strong as concrete. It took me putting all my weight on a 3 foot pry bar to break it loose. Once that is off, the lower valve cover comes right off. It's a few more bolts and a rubber gasket that is reusable under it.
Once that is all out of the way, you can get the injectors out. There are 8 total. There are retainers holding them in place, remove those and the power wires. There are nuts holding the wires on to the injector itself. Don't worry about losing the little nuts, they stay attached to the wires. Once that is disconnected, the injector can be removed from the cup. I used vise grips to clamp on to it. Twist is a little back and forth then slowly start pulling up to remove the injector. DO NOT yank on it, you risk pulling the cup out with it. If that happens, it will be a whole other set of problems since the cups seal out antifreeze.
Once all the injectors are changed, put everything back together, refill the coolant, change the fuel filter, prime the system, fire it up and bleed the coolant system. Change the oil too since there is probably fuel in it.

[Vince@Meanstreets]

Originally Posted by BlueSS454

That would be me . And yes it was a 13 hour job.

It's not overly hard, but is very time consuming. You have to drain the coolant, remove the turbo pipes that go over top of the valve covers, disconnect the wire harness and flip it out of the way then you can access the valve cover bolts. Then you need to remove the fuel filter & pump assembly, disconnect the main fuel lines, leads off the glow plugs, remove the upper radiator hose with the thermostat housing, air filter box and anything else that's in the way.
Next you can remove the individual feed lines to the injectors. You need a crows foot line socket for this.
You will need some metric ball ended hex keys and sockets to remove most of the valve cover bolts. They are not really tight so they should come right out. The hardest part is getting the upper valve cover off. GM uses this sealant that is about as strong as concrete. It took me putting all my weight on a 3 foot pry bar to break it loose. Once that is off, the lower valve cover comes right off. It's a few more bolts and a rubber gasket that is reusable under it.
Once that is all out of the way, you can get the injectors out. There are 8 total. There are retainers holding them in place, remove those and the power wires. There are nuts holding the wires on to the injector itself. Don't worry about losing the little nuts, they stay attached to the wires. Once that is disconnected, the injector can be removed from the cup. I used vise grips to clamp on to it. Twist is a little back and forth then slowly start pulling up to remove the injector. DO NOT yank on it, you risk pulling the cup out with it. If that happens, it will be a whole other set of problems since the cups seal out antifreeze.
Once all the injectors are changed, put everything back together, refill the coolant, change the fuel filter, prime the system, fire it up and bleed the coolant system. Change the oil too since there is probably fuel in it.

no step by step pictures tom?

[HEEP]

Sounds fun. and yes, very expensive. This weekend, I'm putting in a new Fuel Pressure Regulator, in hope that it will stop the over pressure and surging issue I have now. It might bring everything within spec. Probably not going to be my luck, but there is hope.

13 hours seems right from what I have read on other sites. So this weekend will be filled with fun.

[BlueSS454]

I had printed out some papers from an article I found on the internet when I did it then. I forget where I found it though. I can look in my folder I keep in the shop when I get home to see if the link is on there somewhere. If I find it, I will post it

[LS3torque]

LB7 and LMM are both Duramax motors but night and day different on injector swapping. LB7 injectors are under the valvecovers and the fuel lines pass through the cover. In the middle of 2004 the LLY was born, LLY and all later Duramax had openings in the valvecovers so you could get there alot easier and maybe only change the bad injector. I firmly believe the fuel delivery and filtration systems are to blame for most injector failures, too much dirt being forced past the pintle at 27,000 PSI damages the pintle seat then the injector starts to leak. I have a 1 micron Cat primary filter with a 1 micron Donaldson secondary filter fed by twin Kennedy lift pumps. I have over 100,000 miles with no injector troubles. Good luck to ya.

[TheJDMan]

One of the best sources of Duramax info I have found is http://www.dieselplace.com/

[camcojb]

Originally Posted by LS3torque

LB7 and LMM are both Duramax motors but night and day different on injector swapping. LB7 injectors are under the valvecovers and the fuel lines pass through the cover. In the middle of 2004 the LLY was born, LLY and all later Duramax had openings in the valvecovers so you could get there alot easier and maybe only change the bad injector. I firmly believe the fuel delivery and filtration systems are to blame for most injector failures, too much dirt being forced past the pintle at 27,000 PSI damages the pintle seat then the injector starts to leak. I have a 1 micron Cat primary filter with a 1 micron Donaldson secondary filter fed by twin Kennedy lift pumps. I have over 100,000 miles with no injector troubles. Good luck to ya.

I knew it wasn't that hard to swap injectors, but I didn't know there was a change made between the lb7 and the later duramaxs. It didn't take me but an hour or two to do mine so I was sitting here wondering what the heck I did lol.