Recently bought an 88 f250 idi 7.3. Guy that sold it to me said to put the back wheel up on a 4x4 when filling to get fuel into the tank. Still doesn’t work great. Front and rear tanks both never take in more than a couple gallons each and that fuel takes FOREVER to go in because it won’t go down the line without backing up. It seems like they only have a few gallons of free space in the tanks. I have run out of fuel and only been able to add a few gallons before it seems too full to add any more. It seems to me like my fuel pumps are set way to high or something and only skimming off the top couple inches of the tanks. I also think there’s an issue with the fill hose making it back up. Any help is appreciated

 

The old trucks have difficulty with the fuel tanks. The plastic screen on the fuel sending unit deteriorates and comes apart. Then your only able to use the top 1/4 of a tank before you start sucking air.

The fuel tank filler hose also comes apart and prevents you from filling the tank quickly. You can replace the fuel filler hose with an OE piece and use a gas fuel sending unit to replace the bad one. Just use a length of fuel hose on the end of the sending unit and cut a notch in it so it doesn't suck against the inside wall of the tank. There are many threads on our site with pics and explanations on these repairs. Good luck.

 

Could be a few things. If the truck is stock, this shouldn't really be happening. Possible that the tanks' vent tubes are clogged (rollover valve, mine was clogged with dirt when I got it). Also possible that the filler-neck vents are somehow compromised. There is a plastic vent that runs from the top of the tank's full hole, through the filler neck, and "connects" above the hole for the diesel pump. The filler-neck vent on my 86 was pinched when I got it, but a PO had relocated the filler to the floor of the flatbed. Its all redone now, but I could see it being a problem.

 

Apologies for bumping an old thread but I have an 86 IDI that has had PO modifications to the filler for a flatbed that I'm very unhappy with. Could you should me how you've got your filler neck, filler tube and vent setup working?

 

Mike, if you disassemble the fuel filler hose chances are you'll find the internal vent damaged or installed incorrectly. If the inner fuel filler vent is damaged your tank will never fill properly. You can replace the inner fuel filler vent with 1/2 PEX tubing available at the hardware store.

 

I can assure you that I have no internal vent hose to damage. That's why I asked to see previous poster's custom setup. I'd like to see how he manages things as I need a soup to nuts redo of filler/vent situation, for a flatbed.

 

Read through this thread.

https://www.ford-trucks.com/forums/1...-breather.html

I installed a 38 Gallon rear tank several years ago. Installed a new Sending Unit
extended the Pick up Tube, and Float Arm. Also replaced the Shower head with
a new one.

As the picture shows, remove the Roll Over valve from the center of the tank.
Replace the Grommet with a new one, I figured a new rubber would seal
better than the old 28 yr one.
Used a plastic fitting with 3/4" threaded for the Grommet, and 3/4" Barb for the
Breather Hose to run over to the Metal fill tube.
Drilled a hole in the FT, and enlarged it to a size the other threaded 3/4" threads
would bite into the FT. Then JB Welded it.

This is like the one I used.
https://www.lowes.com/pd/B-K-1-2-in-...ing/1000505085
Picture shows 1/2" I used a 3/4" one. Maybe a 5/8" would work as well for the
vent hose.
I cut the neck off at the Hex, reamed out the hole enough for the neck to fit into the hole
tightly. Then use some plastic glue to seal and hold it together.
I cut it off so it would clear the bed floor.

Be sure to use Hose that will hold up to the Diesel. Best to buy it from a Hydraulic
hose shop.
Make sure there is no sag in the hose to the tank. I zip tied to follow the FT to the tank.
If there is a sag, fuel getting in could block the flow of air coming out of the tank as
you are filling it.
I filled up this afternoon, threw in about 29 gallons, and it fills up right now w/o any
burping etc...


Charlie

 

Thanks, I've been reading through all the threads but it seems when it comes to flatbeds everyones got a bit of a special situation. As it stands, I have a vertical fill neck that extends above the bed and attaches to the headache rack, that does a 90 degree and heads over the frame and then down to the tank.

I'd like to replace that with a fill neck with a vent tube similar to those seen here:

https://www.fillernecksupply.com/1-1-2-od-main/

But I've not quite found one that seems like it will fit my purposes yet. The vent attachments seem to big pretty wide off on most of them as they'd made for behind a box:

This looks like the closest as to what I need but out of stock and no reply yet on when it may come back.

https://www.fillernecksupply.com/cab...iller-neck-03/

Hanging off of the edge of the bed doesn't seem like it will be a go with the bed's lip, I think it would have me needing to fuel uphill over the frame. Other options would be going through the deck of the bed in the middle to eliminate navigating the frame but I'm not quite sure exactly how I'd get that accomplished yet. Might need more fabricating than I am currently capable of doing.