The rear tank doesn’t like to take fuel

Wrenchmonkey316

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When I try to fill the rear tank it acts like it’s full. If you pump extremely slow it’ll fill but who wants stand there holding the lever in the the barely pumping position for about 30 minutes. Is there an obstruction or one-way flap that can potentially become an issue? Is there a vent that can plug up and cause this?
 

Jesus Freak

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I suffer from the same thing. Even using my hand pump to fuel up with my oil mix it'll back up really annoying like. I reconciled myself to it as a way to learn patience.
 

DaveBen

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Do you have the vent pipe free of garbage?
 
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Rdnck84_03

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Mine does it on both tanks, the only way that I am aware of to cure this issue is to weld hose barb into the filler neck just below the cap and run a hose from it to the top of the tank where the rollover valve is. This essentially converts it to the setup used on the superduty trucks.

James
 

franklin2

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This is a classic common problem with these trucks. I am surprised I haven't seen it on here like you see air intrusion and fuel pump threads.

Even the gas trucks can have this problem,, but the diesels have it more because the fuel foams so bad. When you are pouring all that fuel into the tank at a high rate, the same volume of air needs to get out of the tank at the same time. There is no where for this to happen except the filler hose.

The factory had a small hose inside the larger hose to try a separate the fuel going in from the air going out. But as you can see it didn't work that well. The best solution I have found was mentioned by the post above. I took out the roll-over valve in top of the tank, but left the grommet in place. I found a copper elbow fitting (I think it's 3/4) just fits inside the grommet, and using a 90 degree fitting keeps it close to the tank top. There is very little room above the rear tank.

I ran this added vent on the top of the tank with a large hose and tied it to the frame. The better option is what the poster above mentioned, putting a fitting in the fill neck. With mine I will get a little puke of foam out of my vent hose when filling the tank to the top at the station. And if you put the fitting in the filler, put it as high as possible. You need to be able to put the fuel station gun past the air vent so the air doesn't interfere with the fuel going in.
 
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Jesus Freak

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I always figured it was because my truck had gotten "augmented" and the vent wasn't done correctly. It's good to know I'm not alone in this.

For safety, and just because a lawyer might read this thread and get ideas I feel inclined to say:

Welding on your fuel cell may be hazardous to your health. It's been known to cause spontaneous death in California and other states not limited to the lower 48, Canada and Mexico. Use caution and wear all OSHA approved safety equipment. Wear your safety belt..... and remember what Smokey the Diesel says, "only you can prevent spontaneous death by explosion".
 

Clb

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Incoming....
In the meantime search
Harpooning the tank
tank vent
tank vent hose mod
filler vent
Rollover valve
Brb
Well seesh guess i failed to bookmark them.
Basically you are removing the 1"+ air vent hose from the filler tube and running an exterior vent to the filler neck using the tank vent port.
While yer in ther do the showerheads.
 

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Clb

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Limit of 5 pics per post.
Showerheads
My way ain't necessarily the best way, there's 3-4 threads here showing you how to get it done...
 

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Greenie

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I've owned my 1993 F250 since new and it's never had any slow fill issues. I can't stick the nozzle in either fuel door and walk away but I can fill either tank quickly by holding the nozzle so it's about 3" in and the fuel stream aligns with the fill tube. Truck stop nozzles are a little more finicky but it still fills pretty well. Just lucky, I guess.
 

Wrenchmonkey316

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This is a classic common problem with these trucks. I am surprised I haven't seen it on here like you see air intrusion and fuel pump threads.

Even the gas trucks can have this problem,, but the diesels have it more because the fuel foams so bad. When you are pouring all that fuel into the tank at a high rate, the same volume of air needs to get out of the tank at the same time. There is no where for this to happen except the filler hose.

The factory had a small hose inside the larger hose to try a separate the fuel going in from the air going out. But as you can see it didn't work that well. The best solution I have found was mentioned by the post above. I took out the roll-over valve in top of the tank, but left the grommet in place. I found a copper elbow fitting (I think it's 3/4) just fits inside the grommet, and using a 90 degree fitting keeps it close to the tank top. There is very little room above the rear tank.

I ran this added vent on the top of the tank with a large hose and tied it to the frame. The better option is what the poster above mentioned, putting a fitting in the fill neck. With mine I will get a little puke of foam out of my vent hose when filling the tank to the top at the station. And if you put the fitting in the filler, put it as high as possible. You need to be able to put the fuel station gun past the air vent so the air doesn't interfere with the fuel going in.
I’m not sure you guys are getting the full picture. It will only accept the equivalent of an old guy labor peeing when the prostate is acting up lol. Ive also noticed on the front tank that same issue of needing to do half throttle and depth/angle adjustment to stop it from popping the handle.
 

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Nero

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I've just gotten accustomed to filling up on the first click for years. I had checked my vent and it was clear. Glad they stopped harassing pumping my own stuff here, I got tired of explaining to fill it slowly.
 

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