Filler neck mod- I highly recommend it!

[ghunt]

There's been a couple posts here about the filler neck mod recently and I was one that posted about it at one point.

I recently did the front tank- opened up the filler neck, 5/8" heater hose for a vent like (couldn't find 5/8" fuel line anywhere locally), with a 1/4" line vented to atmosphere branched off the 5/8" line-I reused the little plastic vent cap things from the original vents and put them a few inches above the filler neck.

I finally got to fill up the truck from a "big truck" pump a few weeks ago- man what a difference. I can't run the pump full throttle...those things just dump out too much fuel, and it still backs up in the neck and shuts the pump off, but you can run it at half and it still pumps a lot faster than your standard "passenger car" pump. I can pump 15 gallons in just a couple minutes. Pretty pleased with it and I really don't have more than $20-30 in everything to do both tanks

 

[1994IDI]

Do you have a picture of what it looks like?

 

[ghunt]

Not really...I could try to get one, but the only camera I currently have is the one built into my phone and it doesn't take very good pictures unless there's lots of light.

 

[hesutton]

I have a few shots of mine below. I used a larger vent hose though. I can run a big rig pump at full tilt. It fills an empty tank in less than 60 seconds without spilling a drop. No BS. It takes longer to pay for the diesel than to fill the tanks.

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Heath

 

[firemedicmonkey]

Can you post some more pics or a diagram of whats going on.. it hard for me to tell... or is there a tech article about it?

 

[LCAM-01XA]

I finally got to fill up the truck from a "big truck" pump a few weeks ago- man what a difference. I can't run the pump full throttle...those things just dump out too much fuel, and it still backs up in the neck and shuts the pump off, but you can run it at half and it still pumps a lot faster than your standard "passenger car" pump.

I have the same results with 1/2" main vent hose and no little vents, half-speed on the big truck pump and fills up twice faster than regular pump...

 

[Mat J]

did you guys gut your filler neck i dont really see the thing that people are talking about removing.

also where did you connect the vent to the filler neck, did you just braze in a 90 fitting or something.

 

[LCAM-01XA]

Yeah, I gutted the fillers, I actually managed to pull the whole inner tube setup on both fillers without cutting anything, just forcing and hammering with a punch and wiggling it out. Then I used a die-grinder on the front filler as that had the smaller opening up top too, whereas the rear filler had no such restriction, heck if I know why. For the vents I drilled a hole on the side of the fillers that would sit on top when installed back in truck, then took some 1/2" OD (has something between 3/8" and 7/16" ID) steel pipe piece I had laying around and cut it in two at 45 degree angle, and then welded the two pieced one at each filler (I like welding and I'm pretty good with it, brazing not so much), and finally stuck the a drill bit of the proper size in the pipe and deburred the hole in the filler in the bottom.

 

[fury9]

not trying to derail here but what is that black box the small clear tube is going to? and is the little clear tube a secondary vent or something?

 

[F350farmboy]

I asked that too and I think its a "roll-over valve" to be legal. It won't do jack in case of a roll over, but its there so he can say, "yes there is"

 

[Andylad13]

I personally like the 2 grade 8 bolts holding up the 1lb assembly!!!

 

[firemedicmonkey]

any one with a rough diagram of this mod... I think i get it... take the vent line and run it back to the tank so the fuel goes in both the fill and the vent...

 

[88beast]

ya id like a write up or if so someone will give me really simple detailed instructions i can do a write up

 

[firemedicmonkey]

yeah I don't mind making really nice write-ups and how-tos with pictures as I do it... This is a mod I think I want todo I just need some help understanding the basics of it... Its hard when I'm 2000 miles from my truck...

 

[Fordsandguns]

any one with a rough diagram of this mod... I think i get it... take the vent line and run it back to the tank so the fuel goes in both the fill and the vent...

You don't want the fuel going through the vent. The reason for doing the mod is to make the vent larger so that it can breath better so that you can fill the tank faster and without it spitting back out the neck.
If the fuel goes in the vent it will defeat the purpose.
The elbow is put on top of the fill neck so the fuel doesn't run into it and block the breathing process.