Should not nees to replace the injector. sounds like the return line thats bad. If I were you I would get a return line kit and just do the whole thing. Only $50 or so and takes maybe an hour if your working slow. Or if you feel like R&D has the new aluminum return rails. Lot more money though.

No Oring under the steel line

 

Yeah.

Um...
Lets sake this from the top.
On the injector side, you have a relatively soft steel line, with a nut on it. The pressure the nut puts on the end of the line ends up deforming it just enough to seal to the taper on the top of the injector. That's the seal for the high pressure fluid.

Below where the nut threads on, you have the black plastic tee(cap). These snap into place over 2 O-rings. The O-rings are Viton, size code #111, and can be gotten on Mcmaster-carr or Amazon cheaply.
When installing the O-rings and cap, clean everything and then lube it up with lithium wheel bearing grease. The wheel bearing grease works well at preventing future leaks and letting things set. The Viton material is not compromised by the grease.

 

Thanks for the help. I'll do some research and order the parts

 

It was bubbling at the top of the injector...so the oring is bad yes?

 

My question is. The return kit does it include injector o rings? I want to change everything since I'll be there. Also my truck is a 94 7.3 idi no turbo

 

Hard to understand the last part of your question....

You can change just the o-rings on the return caps. Most people end up buying a kit and replacing all the caps too, but if you are careful, and the cap is in good shape, you can reuse them and just replace the o-rings and fuel line as needed. However, its generally taken that if you move, even wiggle the caps, the o-rings tend to leak, so you may have to replace all of them on whichever side of the engine you are working on. Probably wouldn't hurt to change all of them if you haven't, make sure you use viton o-rings and grease them well, there are at least a dozen write-ups on here...

The steel lines seal with the flare directly to the injector, no o-ring at all. Some people have put an extra o-ring on top of the return cap to help press it down, but its not necessary and doesn't do anything as far as sealing anything. If you have a crack in the metal line, or the nut to it, you need to replace that metal line.

Edit.. guess I missed page 2 where everyone already said that...

 

The kit I'm looking at has the o rings..fuel lines. Tees and copper crush washers..and hose clamps..I feel like a adjustable hose clamp would be better than the self sealing hose clamps. But I'm obviously new to diesel and I'm curious on how the injector seals....like I said I saw bubbles at the very bottom of the injector going into the engine. And you say caps? Is that the tee? Because one of them is lose on my engine.

 

Yes "caps" is refering to the T. I haven't had any issues with the tension clamps supplied with the kits.

Did you make sure the injector is tightened all the way down? only thing I can think of is last time it was replaced they forgot to put the new crush washer on it. it goes over the nose of the injector that might be where it's leaking. That or it's not tightened all the way.

 

​​​​​​​I have not tried to tighten it I went ahead and got a whole new kit. I'll install it tomorrow