A cousin of mine has a 98 F150 with a 4.6 which he bought used. He changed out the fuel filter but ran into problems. He had the tool that released the line from the filter but one end was really aggravating to get loose and almost didn't come loose. Now the filter won't go all the way in and lock in place. It almost will and you can get the clip to latch but now when you shut off the engine, it seeps a little gas. I'm wondering if a previous owner may have screwed it up. I changed out a few on my 01 and never had a problem. Anyway, it may be he has to replace the line between the filter and fuel rail unless there's some way of replacing the connector. Where can I find a line? How does it connect to the fuel rail? The same as the fuel filter? Any of you run into this problem?

 

I had some difficulty changing my fuel filter the 1st time, much like your cousin.
I kept spraying some WD-40 into the connection until junk stopped running out and the little interior spring loosened up....then it went on fine.

other wise you could get a whole new line on the side that isn't functioning....have ya look at Rockauto?

or cut the steel line ends off and re-flair them ends and get a generic fuel filter with some short pieces of hose and clamps. BUT, that may not have the check valve built in that the ordinal style does, to stop drain back

 

Hose and clamps may not hold up under that kind of fuel pressure.