97 F250 leaking fuel where?

[hr29man1]

I have a 97 F250 with 90,000 miles and have a fuel leak that cannot be found. I have replaces the fuel rail pipe, and rubber washers. There is no fuel to be found in the valley on the passenger side of the engine, or at the rail plugs on the back of both heads. But there is a puddle of fuel that seems to come from between the bell housing and the back of the engine only when the engine is cold. Whats up?

[Turbodude]

how cold is it...because sometimes the metal of the fuel lines will shrink and cause it to leak until it warms up...mine does that sometimes when it drops below 0 here

[hr29man1]

Its about that temp here, the strange thing is you cannot see any leaks anywhere. In Minnesota its cold!!!!!!!!!!

[DirtyDiesel]

there are lines coming from the fuel pump in the valley of the engine that go to the back of the head under the turbo. they mount at the very back of the head up top. check to see if they are loose or cracked or leaking.