LB7: Injector Advice

[gmasko]

Ive posted a few threads about leaking injectors and a coolant pressure issue after i did my injector a while back. Finally tore into it today thinking if the injector cups look good ill go down to the head gaskets. It was injector cups. Numbers 1,3, and 5 all pulled out with the injector and the crush washer on number 7 was canted a bit allowing combustion gas to get past it. Valve covers full of white goo. I stopped working on it today when i stripped the return line bolt head on number 6 , tips on getting that out would be appreciated . i keep hearing about installing injectors the "proper way." This was my first major job and took me an entire week because i took my time with everything to do it right. So id just like to hear what you guys have to say. How do you set the crush washer in the cup and make sure its straight? Since my cups are out can i install the cup with the injector inside? I got the process down just looking for those little "tricks" you guys have, treat me like a dummy

 

[Dmax87]

For the copper washer I usually put a dab of grease or assembly lube on it then put on injector tip, this will make it stick on the injector. As for the cup, clean the head and cup very thoroughly, install new oring, smear red loctite on bottom mating surface of cup, sit down in the head and I use a socket to tap it into place. GM has a specific red loctite they sell and recommend for the cups. Also allow 24 hours for loctite to set up properly before starting engine. You might also look into new injector hold down bolts and do a search on torque spec. Factory torque spec is not enough. Seen to many horror stories on here of combustion passing washers and cups lifting. Good luck!!!

 

[gmasko]

Thanks for the info. Torque spec on the hold downs was 37 ft lbs the first time I did them and that was definetely not enough !!!!!!

Sent from my XT1060 using Tapatalk

 

[pgr11]

Get a good pair of channellocks on the head of the return bolt. Just avoid the mating surface. Should break free no problem. Just had one strip out a few weeks ago when I did my injectors. Brent at Lincoln Diesel has a great write up on doing the injectors. Follow that and you won't have any trouble. If you haven't bought your injectors yet, make sure to buy from him. You won't be disappointed.

 

[DAVe3283]

Trick I found is to take angle cutters and cut the tab connecting the two washers on the bolt (they aren't reusable anyway). Then like pgr11 said, use a good pair of channel-locks, and it should back out. Cutting the washers apart made such a big difference that is the first thing I do now when doing injectors, haven't stripped one since.

If you can't get enough grip on the banjo bolt, even with the washer cut, you might have to cut the return line apart. They are not cheap, but it is always an option. You then spin the return line at the same time as the bolt, and it should come out. If it is just one banjo bolt that is stuck, you can leave the return line attached to the injector, pull it, and then spin the line & bolt out of the truck without cutting it. I did that once, before I learned the trick about cutting the washers.

As for the torque, be careful you don't go too high, as it is really walking a tightrope between the injectors lifting and the bolt stretching/stripping/breaking. Remember, this is going into aluminum... I want to say I did mine a couple ft-lb more than spec, and so far so good. That's with 55+ PSI boost and 100% over injectors, so I am seeing much more cylinder pressure than stock.

 

[gmasko]

So i tried the channel locks this morning but couldnt get a bite, kept slipping off. I had a set of reverse bolt extractors that did the trick. worst part about this was drilling the bolt with the damn upper steering shaft poking out just enough to be in my way hahaha. That bolt alone took about 2 hours out of my day due to finessing my drill around the steering and all those lines.

 

[gmasko]

Then i dinged up 2 cups trying to get them off the injector. No one in town has any so i have wait till monday to take a trip to the dudes at DMax Store. I dont want to lose the entire day tomorrow waiting on cups so i cleaned up the 4 best looking cups and plan on finishing the drivers side tomorrow. Then passenger side when i get cups on monday.

 

[gmasko]

Anyone have any objections or bad experiences with reusing the cups? And ive been taking some pictures that ill post soon mostly cause i took some of how the CA emissions vacuum lines hook up. Might benefit someone someday

 

[THEFERMANATOR]

I reused mine because they all looked brand new when I got them out. Clened em up using some scotch brite pad, washed em with brake cleaner to remove all residue, then put them back in using sleeve retainer loctite.

 

[MrBunny]

if u can swing the money and have the time to wait for shipping u should do youself a favor and buy some injector return bolts from merchant. http://www.merchant-automotive.com/p-5562-ma-heavy-duty-injector-return-line-bolts-at-the-injector-lb7-2001-2004.aspx they will save you one hell of a head ach next time. I have them on now and love it. just clean the injector cups really good and use some oil on the o rings to help get the cup in. use a lot of lock tight on the bottom of the cup and let it set for 24 hours before starting the truck. there are a lot of people that install the cup and injector all at once. i didnt do that I used a soccet sized right and a brass hammer to set the cup in. then put the injector in.

 

[gmasko]

Those bolts would be a great idea, but I can't make up my mind on keeping the truck. That said, I would rather not indulge myself in goodies I won't get to enjoy Im doing with selling it in mind. I bought it with issues I was unaware of. I just want to get the truck running right on a budget so the next owner won't hate me. I got screwed and refuse to be that kind of asshole hahaha.

Sent from my XT1060 using Tapatalk

 

[gmasko]

Sent from my XT1060 using Tapatalk

 

[gmasko]

Sent from my XT1060 using Tapatalk

Here is what I'm using to clean the cup mating surface down in the valve head. I'm using the brass brush which isn't leaving visible marks but is taking a while to clean. Is it OK if I end up scuffing the surface? In my mind it would allow a better grip for the loctite but then again what the hell do I know?

if u can swing the money and have the time to wait for shipping u should do youself a favor and buy some injector return bolts from merchant. http://www.merchant-automotive.com/...line-bolts-at-the-injector-lb7-2001-2004.aspx they will save you one hell of a head ach next time. I have them on now and love it. just clean the injector cups really good and use some oil on the o rings to help get the cup in. use a lot of lock tight on the bottom of the cup and let it set for 24 hours before starting the truck. there are a lot of people that install the cup and injector all at once. i didnt do that I used a soccet sized right and a brass hammer to set the cup in. then put the injector in.

Sent from my XT1060 using Tapatalk

 

[gmasko]

Also the gunk I had inside the valve cover. I didn't take a pic but my pcv hoses were almost entirely blocked with this stuff as well. Assuming that was coolant boiling off in the oil from the 3 cups I pulled

Sent from my XT1060 using Tapatalk

 

[DAVe3283]

Here is what I'm using to clean the cup mating surface down in the valve head. I'm using the brass brush which isn't leaving visible marks but is taking a while to clean. Is it OK if I end up scuffing the surface? In my mind it would allow a better grip for the loctite but then again what the hell do I know?

I used brass on mine, and it does take a while to get the locktite residue off. I would also think it would be OK to get some light scuffs from a stronger brush, but I didn't want to risk it.

Also the gunk I had inside the valve cover. I didn't take a pic but my pcv hoses were almost entirely blocked with this stuff as well. Assuming that was coolant boiling off in the oil from the 3 cups I pulled

Yep, coolant + oil. Been there, done that ([THREAD=63518]cracked head[/THREAD]). It is a pain to get that all cleaned out too.