I did a search for this and nothing jumped out at me.
I noticed I was smelling diesel yesterday so I checked and saw diesel in the valley but couldn't pin point a leak so I hosed down the valley of diesel and then did the obvious first and purchased a new filter, which by the way is a far improved design over the last ones. Anyways when I popped the hood today I saw diesel sitting on top of the filter, good news must be the filter, but after changing it and starting the truck and letting it idle while I put tools and step ladder away I come back to a drip drip under the truck which I don't recall having prior to the filter change, but nothing seen from the top. I creeped under and found the source and since I haven't been on here in awhile I don't know what this hard line is, but if it helps it is towards the front of the block near the bottom and is open at the end kinda like an over flow, next to another hard line that turns back. Is it possible I did something in the filter change process? Any help would be appreciated since I gotta work tomorrow.

 

Sounds like the drain valve on the back of the fuel bowl is leaking. If it is coming THROUGH the hard line that the drain valve is attached to, you will need to rebuild the entire valve (unless maybe it's cocked open a little?). More than likely, it is leaking BETWEEN the valve and the fuel bowl, which is very common, and the fuel might leak down along the drain pipe but not in it. All you need to fix that is a very small torx to remove the 4 screws, and two #202 viton o-rings. If you need the whole rebuild kit, go to dieselorings.com and pickup an entire fuel bowl rebuild kit. Might as well do EVERYTHING all at once.

 

oops......double

 

looks like we were typing at the same time. the orings in this valve are well known to harden with age and leak. like he said it's an easy, inexpensive and common fix.

While your in the valley look for another hard line that runs along and inside the passenger side valve cover. towards the back of the valve cover it goes through a hard clamp which has been known to rub through. since you have fuel in the valley you may want to check this one too as it will spew lots of diesel when it finally lets go. if it's ok you can wrap the line with a small piece of rubber or teflon where it goes through the clamp to prevent it from wearing through in the future.

 

Yup! You have discovered that the water-drain valve has developed leaky o-rings.

Happens all the time.

The best ones to replace them with are here:
Ford 7.3 Diesel Fluorosilcone Drain Valve O-rings

Also, while you're in there, heed Paul's advice about wrapping the passenger-side fuel-feed line to protect it from wearing inside of the clamp.

Pop

 

You might be able to temporarily stop the leak by snugging up the 4 torx screws that hold the valve to the bowl. It'll buy you some time while you wait for the new o-rings to get there.

 

Thanks y'all, and it is coming through the line. Wasn't doing it before I changed the filter and its no longer leaking in the valley. But I'm gonna order those o-rings etc... and try to snug those torx up

 

Check and make sure thatyou didn't bump the yellow lever partially open, causing the leak there.

 

Slowed the leak but still a smaller drip drip. I went ahead and bought the entire new valve assembly in case I gacked up the torx screws since it comes with new screws. Thanks again ya'll

 

I did the same when mine went last month. I knew it was much more expensive, but I didn't want to mess with taking the valve assembly apart and such. Hope it cures your leak!

 

$6.75 for the O-rings. Very easy job, very little room for error, very rare you need more then just the O-rings. Took me about 30 minutes, the longest part was cleaning the yellow O-ring debris off the plastic valve.

IMO you should climb under the truck, reach up and take out the one bolt that fastens the drain tube to the engine. This will allow a little play while trying to pull the rubber line off the plastic valve. This is the one area to be careful and not put to much pressure on the plastic while removing and reinstalling the hose.

 

The part of the valve I didn't want to do was disassembling it down to the white plastic components with that little check ball and doing that O-ring.

Anyway, it seems that the OP has already gone ahead and bought himself a brand new assembly. Now he has a spare, and doesn't have to worry about breaking the nipple on the old one.

 

Seems the -5 to -7 temps have created a "rash" of leaking 7.3's - I've fixed 4 since the "polar vortex hit", maybe I need to buy some stock in an o-ring supplier !

 

Thought I'd let y'all know I had changed the valve and that certainly solved the problem and the fuel gauge has slowed it's decline somewhat. Also Bobbykjl is correct that would have made it easier but what would have made it a breeze was if I had the hands of a 3 year old, jeez I never had my hands so contorted before 8)

 

Ha. Most of us know the feeling!!! In some ways, it's easier to remove the entire fuel bowl and do it out of the truck. That's why a lot of guys simply rebuild their entire fuel bowl when that happens. It's overkill if you've rebuilt once already, but sure prevents the frustration of no-space for the hands and knuckles.