Since I have recently installed newly rebuilt injectors, I have about 1,000 miles on them, I have a fuel leak on the number 1,3 cylinders coming up from around the hold down nuts. #1 is very slight, but #3 is fairly significant. They have been leaking since install, I just hoped they would stop on their own.My question is, how do I stop the leak, and could the injector body itself be cracked? The truck runs very well. The truck has no starting issues, as would be from sucking air. I did use new washers.Thanks

If they are like mine I mess with them for a few days and they finally stop. Keep tightening and loosening them and they will eventually stop.

How did you tighten them? Did you have to pull lines or were you able to use a crow's foot?

Flare Nut wrench and torque mine..

In my experience the fuel line nuts are simple, injector hold down nuts are simple, the return lines on each injector are the issue. Those little horseshoe copper washers just don't like being messed with. You might try tightening them some more but I have fought a leak for a while now, finally got it to stop but those things really suck, especially when you wear them out like I do taking them out all the time. Copper seals by being smashed into all the crevices so you can't just snug them up. Give those 2 a little more torque. Should be around 10 ft/lbs. If they are still leaking you might have an indention in the washer that is too big to "smash" down flat so it is just leaking through it. To really be sure, let the truck idle and get an air hose and blow down the whole injector so it is completely dry and then watch the leak because that fuel has a way of seeping everywhere and making it look like something else is leaking.

I actually had a leak from the return line initially, but finally got it to stop. The fuel is coming up past the hold down nut, actually took it to a shop and had them take a look. They did the same thing you are talking about, blew it with air and watched, and they agreed it was coming past hold down nut. They said the only way it would leak from there was the injector body was cracked or the nut at the end to the injector had backed off.

In that case you could put them on a pop tester and pump them up to the point right before it pops and see where it's leaking.

Would you really think that the injector could be cracked? Or would it be more likely that the hold down nut just needs to be tightened down? I don't know if it would be possible for fuel to come back up past the washer on the injector tip after being injected into the cylinder.

You are correct. But since you say it is definitely down there somewhere, it has to be either a crack or they just didn't tighten the injector halves enough. A pop test would show the leak since you can lock the pressure and just let it sit there and watch the leak drip.