Lb7 cp3 replacement

[Dirtymax83]

Hi all. New to the group and to diesels. Been wrenching professionally for 15 years. Replacing the lazy cp3 with a new lbz. I'm wondering what I need to grab for gaskets/o-ring before I start, so I don't end up with it stuck on my hoist, waiting for parts. Thanks in advance.

 

[DAVe3283]

Looks like 2 o-rings on the CP3 adapter are non-reusable.

Trying to remember what all has to come off to get the pump out.
I think the Y-bridge has to come out, but I've re-used those gaskets for 315,000 miles so far with no leaks.
If the coolant tube has to come off the thermostat housing, I recommend replacing that gasket. Same with coolant feed to heater core, but that probably can stay on the truck.
The fuel lines don't use gaskets, except where the return lines go into the head. If that has to come off (I think it does), get new crush washers for the banjo bolts. I've re-used them without issue on the outside of the head, but better not to IMO.
I'm probably forgetting some. My truck has had a custom fuel system for so long I can't remember what stock ones looked like anymore...

 

[Dirtymax83]

Ok. Thanks. I was wondering on the y bridge. Is that a steel gasket, or just that they hold together good?

 

[BlkMax]

It's a rectangular shaped o-ring. They can be a pita getting it shoved back down to seat. I've always replaced those, too much time spent to have a leak. If you are running stock or near stock tuning with a stock turbo, you may be ok.

FYI, the GM y-bridge rings are "thinner" than aftermarket. I had some heads which were milled on the head face, but not on the intake side... I had to use the GM orings (I just happened to have GM set in the shop) because the AM ones in the kit would not compress enough.

 

[Dirtymax83]

Thanks for the info guys.
:beer

 

[clrussell]

Best I rememeber you don't have to pull the y bridge.. Just pull the coolant crossover and all the fuel lines.

 

[Dirtymax83]

Ok. Got the lbz pump on. Knew it would need a retune, but it is running 140Mpa at idle, with a LOT of rattle. Is this just because of the larger pump/different regulator combination? Will it be cured by a tune?
Anybody have any experience with lb7 to lbz swap?

 

[$chultz38]

Retune it or put the lb7 regulator in

 

[nwpadmax]

Yeah if you're leaving the same tune in it, put your old FCA/FPR back on. I just put 2 LBZ pumps on my LB7 and it runs fine with the old FCAs.

I also bought stainless allen head screws to replace those idiotic torx screws, makes the job a bit easier when/if you have to swap or change them. However, a magnetic fishing tool is no longer of any use

 

[Dirtymax83]

Is there any benefit to one regulator over the other? I mean is the pump capable of more pressure than the lb7 regulator can command?
Is it better to keep the lbz regulator and tune it, or swap the regulator and keep my current tunes?

 

[clrussell]

Is there any benefit to one regulator over the other? I mean is the pump capable of more pressure than the lb7 regulator can command?
Is it better to keep the lbz regulator and tune it, or swap the regulator and keep my current tunes?

I'd retune.. Kinda defeats the General purpose everyone does lbz pumps

 

[bmc1025]

Most tuners will update the tune for your swap. If you have efilive and an unlocked tune its fairly easy to fix.