LB7: Replace Head Gaskets

wkwildman

New member
Sep 13, 2015
2
0
0
I am relatively mechanical and the head gaskets are blown in my LB7. I keep hearing all these horror stories on changing head gaskets on a duramax. I have never done one although I have changed many head gaskets on gas engines. How bad is it? I am open for pointers and suggestion? Local shops want 8 grand to do the job and I don't have that kind of money!
 

02greysixer

Active member
Jun 4, 2011
1,829
7
38
North Central FL
Just have the heads checked when you get them off. If you're comfortable with gassers don't let the lb7 scare you. Good time to have injectors tested too unless they're new. Be surgical clean with any of the fuel system. You may get lucky and just find a bad cup

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02greysixer

Active member
Jun 4, 2011
1,829
7
38
North Central FL
The shop I work for is high, around 5k without injectors. Wonder if their quote included 8 new injectors and cups. That would help close the gap. 8k is still way high though.

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Apr 15, 2015
419
2
18
dallas
I did mine with out any diesel knowledge but like you have done a lot of gas stuff. These lb7s are pretty simple once you get in there and mess with them. I did pull the cab but I have a two post lift. Only took two hours to pull the cab. And probably saved me 6 hours and a sore back. When you pull the injector lines crap will fall down into the injectors from the high pressure lines. Use a vacuum to suck the trash out if your going to reuse the injectors. I resealed all my cups. Didn't want to take the chance. My only regret is not buying studs.
 

wkwildman

New member
Sep 13, 2015
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I did , I just looked at him and said oh you were serious!


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catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
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36
NE Oregon
I do them for 3600$ out the door with studs. most of the time I talk them into new injectors/hp lines. and then if they need all the fuel hoses in the valley and to and from the filter replaced I get all those from GM for another 250$ and rebuild the filter base. new fuel filter oil and filter and coolant (included in the 3600$). doing the second one now that wanted 30% over injectors so his is 3600+3,000 for injectors and lines, and then he is having me do EFI live DSP5 so there is another 475$ since he has the edge Insight CTS already. (no DSP5 switch needed) so this guy is getting all that for under 8K and I make about 3K all said and done in about 12 to 14 hours. not a bad lick for a couple days labor. :thumb:
 

WolfLMM

Making Chips
Nov 21, 2006
4,005
26
48
38
AL
I am relatively mechanical and the head gaskets are blown in my LB7. I keep hearing all these horror stories on changing head gaskets on a duramax. I have never done one although I have changed many head gaskets on gas engines. How bad is it? I am open for pointers and suggestion? Local shops want 8 grand to do the job and I don't have that kind of money!

Not hard. No magic involved. The guys on this board can walk you thru it. It's not hard, just a lot of work.
 

catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
to me these are sop much easier then 6.0's after doing a few I don't really care to work on 6.0's anymore. cab is easier. heads are lighter. don't have to remove the turbo or that horse shoe shaped intake.
 

Awenta

Active member
Sep 28, 2014
4,090
2
38
CT
Just take your time so you don't overlook anything.

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MrBunny

New member
Sep 14, 2015
37
0
0
39
Lake City, FL
I did mine with out any diesel knowledge but like you have done a lot of gas stuff. These lb7s are pretty simple once you get in there and mess with them. I did pull the cab but I have a two post lift. Only took two hours to pull the cab. And probably saved me 6 hours and a sore back. When you pull the injector lines crap will fall down into the injectors from the high pressure lines. Use a vacuum to suck the trash out if your going to reuse the injectors. I resealed all my cups. Didn't want to take the chance. My only regret is not buying studs.

man i really wish i had a lift. it would of saved me so much time and blood. lol. I have had messed up bolts and all that fun.
 

clrussell

pro-procrastinator
Sep 23, 2013
5,928
399
83
to me these are sop much easier then 6.0's after doing a few I don't really care to work on 6.0's anymore. cab is easier. heads are lighter. don't have to remove the turbo or that horse shoe shaped intake.


If you unbolt the heads and drop them down you can pull the heads without pulling the intake or turbo..


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catman3126

Ehhh?.... You don't say?
Jul 24, 2012
2,636
0
36
NE Oregon
If you unbolt the heads and drop them down you can pull the heads without pulling the intake or turbo..


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correct but everyone ive done I do the oil cooler, stc on the newer ones and egr delete. so pretty much all the top end
 

trevorpust

New member
Oct 11, 2015
1
0
0
Every once in a while antifreeze will come out of the over flow. It doesn't overheat and there's no white smoke? What do yinz think?


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