I am going to tell on myself - hopefully someone can learn from my mistake, but I do have a question...

I noticed oil spots under my truck last week. Got under there and the oil was really thin and runny coming off the back of the pan. Come to find out after inspecting the valley, it wasn't an oil leak but rather my fuel drain valve leaking and picking up old oil as it ran down.

I got the dieselorings.com complete fuel bowl reseal kit with the blue military grade o-rings and installed it this weekend. I don't regret buying the whole kit because some of my fuel sleeves were shot, too. However, somehow I must have goofed on the heater/water-in-fuel sensor because it was spraying fuel upon priming the filter housing. In desperation of not wanting to pull the fuel bowl back out, I tried re-tightening the screws on the sensor. One screw just kept spinning without tightening. I thought I was being cautions enough not to over-torque these but I must have cross threaded it

So, I started shopping for a new fuel bowl. There are 2 Motorcraft OEM part numbers. Some assemblies I have found will contain both part numbers: F81Z-9155-AC and FG1057. When I search for "FG1057" only I find cheaper prices on rock auto and amazon with identical photos as the "F81Z-9155-AC" from the same suppliers - both complete with all sensors and fittings. Both numbers are listed as cross references to the other. Can anyone explain why the 2 part numbers for what seems to be identical parts by the same manufacturer?

I plan on switching over the blue o-rings to the new drain valve that will come with the assembly. Would this be advisable or not since they've already been installed?

 

You can probably get away without buying a new fuel bowl simply by picking up a US thread screw, slightly larger than the metric screw that is original. Re tap the hole to the new screw thread and you should be good.

It is common to strip the threads on the drain valve and WIF/Heater with the soft aluminum that the bowls are made from.

Bob aka "Guzzle"

 

I second his advice. The screw itself isn't closing a hole with fuel, but putting pressure to valve to seal it to the bowl body. Just need to get it to grab enough to pull it snug.
Also since you mentioned the heater, if you removed the bowl cap, make sure the gasket is on correctly and not pinched or turned. Or the cap itself could be loose.
I had mine that wasn't quite "right" and it drooled fuel down the side of the bowl right past the valve. Looked like it was the valve that was leaking until I actually stuck my head over the top to get a better look and saw it drooling from the cap.

 

This was considered but wasn't sure about losing that metal sleeve inside the sensor when re-tapping it for a larger size screw. If it isn't that important losing it, I may try it then. Couldn't hurt at this point anyway. Thanks!

 

You should be able to get a US thread screw that will be larger than the original but still fit inside the metal sleeve without having to do anything with the sensor, just re-tap the bowl.

 

Definitely not the lid, but thanks for the suggestion. I see it spraying with force from behind the sensor. One of my screw heads is free spinning, not tightening, so I am confident it is my issue. I know the screw does not penetrate the bowl but it does not seal the sensor as you said, thus my leak.

I have made a run to the hardware store and found 1 size bigger in standard but the 3/4" length is about 2 threads too small and the 1" length is about 2 threads too long. I am thinking I need to use the 1" and grind off the last 2 threads, correct?

 

You can cut whatever you need to off the bolt but if you pick up a tap, make sure that it is a 'bottoming' tap, not a tapered tap for the thread pitch you need.

 

Got it! Thanks Guzzle!