I have a 1997 F-250HD with the 460. The rear tank has not worked since I got the truck a month ago and the previous owner said it had been years. I'm putting a 5th wheel hitch in the truck and had to drop drop the rear tank out to get to the underside of the bed. The tank is in pretty rough shape and I decided to replace it at a later date because of the expense. One fuel line disconnected, the other broke in the effort. Can I just block off the lines? One of them is dumping fuel. I guess I misunderstood about how the fuel lines run in these trucks.

 

Dont worry about the exterior appearance of the fuel tank. Look inside and see if its rusty. If its nice and clean inside, purchase a new Fuel Delivery Module and drop it in. Youre truck only get about 8mpg while towing, so 20 gallons in the mid tank goes really fast. You'll be really happy to have the extra fuel onboard.
You can repair the broken fuel line fitting.

 

Yes, that was the plan. The retaining ring was rusted right to the assembly and the tank so that it all kind of went to hell. It'll all need to be replaced, and I will do that eventually. Right now, though, I've just spent too much money on everything else.

One of the fuel lines REFUSES to disconnect. After things went south with the fuel tank, we just cut the line on the tank side. Anyway, it still refuses to release. Is there some trick? Can I cut if off and get a new connector?

 

I wouldn't cut that quick connect off - I don't know whether it's possible to make a new fitting or whether you'd be buying new line for the rear tank - someone will chime in and let you know for sure.

As for your other question, yes it's possible to run only one tank. What you'll want to do is disconnect/drop the old tank, then create block off pipes out of your old FDM (tank fuel pump). I just used rubber line and corresponding sized bolts with hose clamps. Block both off so no debris get inside. Truck should run just fine and not leak fuel out of the return line for the back tank.

The way these fuel systems work is that you've got 2 sets of feed and return lines that merge into one up near the fuel rail under the hood. Inside the tank, each FDM (fuel delivery module) has a "check valve" that will NOT allow fuel to flow back to the tank. When the FDM is energized, it holds the check valve open on that tank, allowing return fuel to go back to the original tank you're feeding from. The other FDM, being non-energized, should have that check valve closed not allowing fuel to pass to the other tank. Classic symptom of a failing FDM is that it's allowing fuel to be returned even though it isn't operating.

 

Thank you for the explanation. It makes sense now. I blocked off the lines like you suggested. I also purchased a new tank and fuel pump. Still though, can't get the old line to release. Very frustrating. I feel like an idiot. Maybe they're child proof.

 

What style of disconnect tool are you using? Have you tried a different style? I fought the one on the Bronco fuel filter but it eventually let go with enough penetrating oil and patience.

 

There are 3 common types of connector tools to release the quick connects on a EFI Ford tank.

Clam shell spring loaded, a scissor type & the cheap, white split type on a plastic storage rail.

Only the 3rd type works, the others are too short to reach the "basket" spring.

Problem is that dirt gets under the "fingers" of the basket which will not allow them to be pushed away from the collar on the line.

It takes a lot of solvent & compressed air to clean out the dirt, freeing up the fingers, so that the tool works.

Usually by push/pulling the connector while keeping the tool forced into the connector.

You can plug the lines by taking a dead fuel filter cannister & cutting off the long end & crushing, then folding/flattening the cut end to seal it.

The larger 3/8 connector can be plugged with a joint of 3/8 copper tube also flattened/folded, then inserted into the connector.

I also put a dab of silicon in the tube before flattening. If you're really worried it won't seal, you can take some JB weld metal stick & make a "pill" to stuff into the tube plug & pack with a drill bit end.




Install the line clips to keep the plugs from blowing out.

 

Only the cheap, white split type on a plastic storage rail works? These are what I have:



They worked okay on the other line. I can definitely see how the filth would gunk up the works. I'll just keep working it I guess.

I left some rubber fuel line on the ends, stuck a bolt in it, and put clamps on the line. I'm barely driving the truck, but sometimes need to. Can't reinstall the tank until I get the 5th wheel rails welded on Monday anyway, I guess.

Thanks!

 

That is what I have for fuel and a/c lines. When I worked at Ford dealership in the mid 90’s I tried the other types but they didn’t work as good. I have a set from Lisle and they would always work where they other types would not.

 

As long as the depth or "reach" of the tool is just a little under 7/16ths of an inch they should be fine.

This is what you're trying to push out against as to release the collar on tube.

You can see if it has any dirt under the fingers, doesn't matter what tool you use:

 

This is the Lisle set. They have a non-fixed throat that can shift around the tube some as to engage the fingers of the connector that doesn't appear as symmetrical as you'd think.

 

Dunno if you got this taken care of yet, but just wanna throw this out there. Some of the fittings have a nylon spacer between the O-ring and the connector body, that tends to get "rust-welded" to the nipple. On a truck that's as rusty as it sounds like yours is, it's common to yank the fitting off and find its guts still on the nipple afterward, meaning the fitting is more or less useless at that point.

A temporary repair that works fairly well to get you home is to just cut off the fitting and slip a piece of rubber fuel hose over both the nipple and the end of the fuel line where the fitting used to be.

Do you have the black plastic fittings, or the stainless ones? If the former, you can buy replacement pigtails with a new fitting, but they're a PITA to install correctly.