Fuel leak, not the return lines

[Lonewolf182]

So I've got a slow fuel leak somewhere on the top of the engine.
The return lines are new and staying dry but I'm getting fuel in the valley and running down the back of the engine.
I've checked the injector lines at the top of the IP and they're snug. Can't really get to the lower ones.

Any ideas on where I should look or what I should try?

 

[miles1400]

the feed line from the filter head to the center of the ip, they tend to weap/leak.

 

[rhythim]

the feed line from the filter head to the center of the ip, they tend to weap/leak.

This. Mine developed a hairline crack right at the tight bend before it connects to the IP. Good opportunity to replace the seals on each end, too, because they were hard as a rock.

Sent from my SM-G988U using Tapatalk

 

[Lonewolf182]

Thanks folks, I'll check it out.

 

[IDIBRONCO]

A seal in the pump could leak too. An inspection mirror will let you see the lower lines on the pump if you position it right.

 

[Joseph Davis]

Check the fuel return lines bolted to back of driver side head. Some have a small tin line there that rot-out over years of service. Mine did

 

[Fredrickson]

I had a leak at the filter head that was dripping down the back of the engine soaking the starter..

 

[Lonewolf182]

Ok, more to look for when i get a change.
Been playing catch up with work because of the down time caused by the tranny.
Had a little time today but decided she needed an oil change more

 

[Dane Rickford]

What I always do when I have a mystery leak is in fold up a light colored shop towel and slide it into the valley pan beneath the injection pump and injection lines. Once the towel is in place I let the truck idle for 5-10 minutes and then shut it off. Then using a bright flashlight I inspect the towel for any moisture before removing it. After I pull the towel out I inspect it again. If there are any leaks at the pump or front sections of the lines this method usually finds them with ease. I use a light colored shop towel because it is a lot easier to see any moisture on a light color than a dark color. Good luck!

 

[IDIBRONCO]

What I always do when I have a mystery leak is in fold up a light colored shop towel and slide it into the valley pan beneath the injection pump and injection lines. Once the towel is in place I let the truck idle for 5-10 minutes and then shut it off. Then using a bright flashlight I inspect the towel for any moisture before removing it. After I pull the towel out I inspect it again. If there are any leaks at the pump or front sections of the lines this method usually finds them with ease. I use a light colored shop towel because it is a lot easier to see any moisture on a light color than a dark color. Good luck!

Yep. It works well. Just be sure to dry off the valley pan first.

 

[jrollf]

Another place to check.. I believe there is a weep hole in the bottom of the IP. If fuel is coming out there you likely need a new IP.

1993 F350 Crew Cab Dually
7.3L IDIT with a Banks Sidewinder
ZF 5-spd manual transmission

 

[Lonewolf182]

Ok finally had some time for the truck.
Ever get the feeling that your truck is out to make you look stupid?
I drove her up on ramps to tilt the engine back and hit the top with the air compressor. Pulled the filter box and the valley pan was bone dry.

Decided to check things out anyway. I put an absorbent pad under the IP and ran her for 10 minutes, nothing.
Then used a mirror to check the bottom sides of the metal lines. No cracks or drips but the last 1/4" of the bottom of the lowest line on the passenger side is suspiciously clean.
I recently did a seafoam hot soak, could that have softened the rubber seal?

I tried to tighten that line with a crow's foot but wasn't able to. Is there a way to tighten it without removing the other lines first?

And I still have a fuel leak.
It's dripping off of the drivers side frame now. The return line runs there so I'll check it the next chance i get.

 

[IDIBRONCO]

lowest line on the passenger side is suspiciously clean.
I recently did a seafoam hot soak, could that have softened the rubber seal?

By this, I'm assuming that you're still talking about the injector lines on the pump. They don't have rubber seals.

 

[Lonewolf182]

By this, I'm assuming that you're still talking about the injector lines on the pump. They don't have rubber seals.

I am. I thought there would be inside the fittings.
I know there were on the line that ran from the filter to the pump on my old 6.9

 

[IDIBRONCO]

I am. I thought there would be inside the fittings.
I know there were on the line that ran from the filter to the pump on my old 6.9

That line has to deal with far less pressure than the injector lines do. I believe that the steel injector lines use a flared fitting to seal. That may not be the correct term, but the seal is done by only steel.