Considering DD'ing 350k mile LB7?
- Thread starter fl0w3n
- Start date
Don’t loctite anything going back together but torque shit down as it should be. Socal Diesel website has a torque spec list for you to follow.
I agree in principle about resealing the cups. That said, on banks where every cup stays put, I've always just left them and been fine. But I know I'm rolling the dice, so if you leave them and one leaks, remember you chose to take that risk.
I always have used hi-temp threadlocker red on the cups and been fine. I don't know if that's a direct cross to the GM part number, but it does work fine for me.
As I get older, I'm starting to lean more towards resealing the cups regardless because the full day pulling injectors again is less and less fun. Even though I've never had to, I don't relish the thought...
Don't use blue threadlocker on things. As stated, torque them exactly to spec and you'll be fine. This is most critical on the return line banjo bolts and high-pressure lines, IMO.
I always have used hi-temp threadlocker red on the cups and been fine. I don't know if that's a direct cross to the GM part number, but it does work fine for me.
As I get older, I'm starting to lean more towards resealing the cups regardless because the full day pulling injectors again is less and less fun. Even though I've never had to, I don't relish the thought...
Don't use blue threadlocker on things. As stated, torque them exactly to spec and you'll be fine. This is most critical on the return line banjo bolts and high-pressure lines, IMO.
Oh and my turbo has some up and down play to it 
I just assumed it would based off the rest of the truck, but I already decided to skip it because of budget. Other than literally already being there ready to replace it, will I regret not doing it now? I’m worried about running Dave’s tune and it working the turbo harder and destroying it fast. Should I just adjust for the SAC45s and keep it stock for now?
I just assumed it would based off the rest of the truck, but I already decided to skip it because of budget. Other than literally already being there ready to replace it, will I regret not doing it now? I’m worried about running Dave’s tune and it working the turbo harder and destroying it fast. Should I just adjust for the SAC45s and keep it stock for now?
Perfect thanks
I’m not quite ready to torque yet, I want to relash valves and I lost my feeler gauge. Nearly every valve has play, despite cam location.
Haha no need to brag, I’m at about 35 hours and just barely getting the injectors out.
But it is my first time, and Im doing the CP3, water pump, harmonic balancer, and getting rid of the egr
I know. I just wasn’t sure if I was supposed to loctite anything else based off things being loose when I got in there.
Depends on how much play. A tiny amount is normal, but if you think it could hit the housing, probably not long for this world. If you leave the wastegate stock (no boost fooler added in line) and avoid heavy throttle, that should buy you quite a bit of time.Oh and my turbo has some up and down play to it
I just assumed it would based off the rest of the truck, but I already decided to skip it because of budget. Other than literally already being there ready to replace it, will I regret not doing it now? I’m worried about running Dave’s tune and it working the turbo harder and destroying it fast. Should I just adjust for the SAC45s and keep it stock for now?
What's hardest on the turbo isn't necessarily boost, but compressor surge. That happens if you are at high boost and snap off the throttle suddenly. The compressor side is trying to be back driven by boost in the intake, and the exhaust flow cuts back instantly due to no fuel injected. This creates all sorts of bad loads on the bearings. So try to smoothly roll off the throttle when you're under boost, if possible.
Edit: it takes me a full day per side to do injectors. I wish I could do all 8 in a day!
I like that.no possibility of abrasives in the cylinder.i did mine with the heads apart so no biggie.i used the red stuff from LDS on the cups and its been fine so far.
The turbo is easy to rebuild. I used a brand that yellow chevy mentioned for the rebuild kit.turbo connection? Midwest turbo? Something like that. Port and polish is easy too.....
Hmm, I’ll see if I can measure it somehow... but I tried wiggling it while rotating to see if it hits anything and doesn’t seem like it... but it’s kinda hard to do.
Good to know about surge, I think I can try and manage that.
Ha okay, I guess that’s a bit better.
Any way you can look it up who yellow Chevy recommended? I’d rather rebuild than go bigger, based off the discussion a few pages ago.
I just got concerned with rebuild kits when I didn’t see any of the main suppliers I know of carrying them.
Midwest turbo connections. Look up his IHI rebuild thread(and his others).very helpful! Its easy to bend fins so you might pick up another ihi to do your tinkering on.
Two questions- what is the o ring at #20 called? Was pressure washing the front end and accidentally blasted that thing into orbit.
Also, is this diagram and others like it from All Data? I’m considering getting it for this truck.
Edit: also, no banjo washers are to be reused correct? I completely disassembled the fuel system at the motor and I don’t think the injector master install kit from LDS comes with every banjo washer I need, so I want to order up what I don’t have.
Thanks! I may just opt to send it in and have them rebuild it. Price seems fair.
But I think that will have to be at a later date, I’m hoping this one isn’t too bad and I can get it to last a bit.
Crush washers can be reused but it is not recommend. With that being said I have done it many times. Copper work hardens quite easy and each time the washer is crushed it gets harder. The best way to reuse them if they look in good shape is to heat them with a torch to a dull red. This anneals it and makes them soft again so you can get more crush out of them. I'll admit I've crushed some upto three times without annealing them but it is best not to do it that way
You also can't reliably use the torque specs any more ether. You have to torque them until the copper crushes and you can feel this as a leveling off or plateau of the torque rise as you tighten the bolt. You want to stop just after that, maybe a quarter turn or so.
Do a few and you'll get the feel of it
I usually get a top end gasket set from Mahle and it includes #20. The GM dealer will probably be able to get that part, otherwise you'll have to get a set that contains it. The LDS set might or might not have that o-ring.
AllData should have diagrams like that. Some sort of service information is really useful when doing work on these motors.
I've found the LDS gasket kit doesn't come with a ton of different washers you need. I never re-use a banjo washer under the valve cover, not worth the risk. The injector kit should come with the long ones for the return line, but the short ones are hard to find outside of a full gasket set. When I did injectors on my Suburban last, I ended up ordering the full stock of every GM dealer in the state for those banjo washers, and was still short one. (Had to be on the road that weekend, couldn't wait for RockAuto or similar.)
If you do end up not having enough of the short banjo washers, put 2 new ones inside the valve covers, and the used ones on the external fuel system, with the nicest ones going to the hardest to reach spots. Then if one leaks, it's not too bad to change later. Did that on the Suburban, and so far so good, but I rest easy knowing the internal ones are new, so any leaks will be external.
Two questions- what is the o ring at #20 called? Was pressure washing the front end and accidentally blasted that thing into orbit.
That would be the coolant bypass lower "O" ring or "seal"
I believe the part number is 94011603
Interesting okay, I'll keep the annealing method as an option.
The LDS kit should have me covered under the valve covers. I actually just called them as well and got the part numbers so I'll order some spares.
From what I understood there are only 3 sizes of banjo washers used throughout the motor?
Smallest on the injector return lines under the valve covers
Mid sized on all the lines outside the valve covers
Large one on just the FPRV
I think I'll just pull the trigger on the AllData then, I think it'll help seeing blown up diagrams like that to remember where all the little brackets went. That's one of my biggest fears right now is remembering that haha.
I’m also planning on converting this thing to FE9 Federal from YF5, I got a federal up pipe, gooseneck Y bridge, and federal belt.
But I’m wondering, #35 in the diagram I posted goes to the EGR, can I just plug this coolant tube with some rubber line and a bolt and same with the one at the firewall? Any other stupid little things I’ll havr to worry about not bolting the egr and vacuum pump back on when I go to put everything back together?
But I’m wondering, #35 in the diagram I posted goes to the EGR, can I just plug this coolant tube with some rubber line and a bolt and same with the one at the firewall? Any other stupid little things I’ll havr to worry about not bolting the egr and vacuum pump back on when I go to put everything back together?