The rear tank doesn’t like to take fuel

[franklin2]

Found a good writeup on how to do a better tank vent mod

1994-1997 Power Stroke FAQ - Fuel Tank Vent Mod

www.thedieselstop.com

Not sure why that guy in the article had vacuum problems with his tank. I thought all modern fuel caps let air in, but not out.

I ran into the same problem he did, not at the beginning, but later on when one of my hoses fell down. I filled the tank and some fuel got in the belly of the vent hose where it fell and sagged. I finally figured it out and lifted the hose and got the fuel out of it, then everything was back to normal. You definitely need a constant downward slope on the vent hose so it will stay drained of fuel.

 

[Wrenchmonkey316]

Not sure why that guy in the article had vacuum problems with his tank. I thought all modern fuel caps let air in, but not out.

I ran into the same problem he did, not at the beginning, but later on when one of my hoses fell down. I filled the tank and some fuel got in the belly of the vent hose where it fell and sagged. I finally figured it out and lifted the hose and got the fuel out of it, then everything was back to normal. You definitely need a constant downward slope on the vent hose so it will stay drained of fuel.

Thank you. I’ll check it.

 

[Clb]

In a fwiw tech 101
I got this one from my kid who was a master tech @ ford ...
He would pull the driver side bed bolts and loosen the pass side all the way and jack up the bed.
Its a pita but you rust belt guys know why.
Just enough room to get the job done.
The deiselstop link is a good one.
Realize that the (?rear?) rollover valve is REALLY REALLY close to the bed, so measure closely when modding it.

 

[Delly]

Where does the stock roll over valve vent hose for the rear tank exit at? I’ve looked all around the tank and can’t find the thing. I’ve had problems with mud daubers plugging my rear diff vent, and I’d like to check this since I’m hearing vacuum when I open the fuel cap.

Also, it sounds like there should be a plastic fitting in the end of the vent hose to prevent this, does anyone have a part number for it?

 

[Clb]

You won't be able to see it without lifting the box...
It's like a 3/8" line sneaking out between the box and tank the clipped to a flange if I recall...

 

[IDIBRONCO]

You won't be able to see it without lifting the box...
It's like a 3/8" line sneaking out between the box and tank the clipped to a flange if I recall...

The valve itself is on top of the tank.

 

[WrenchWhore]

This is definitely a mod I need to do with my 38 gallon rear tank. I feel bad being the guy taking forever to fill his truck. Sometimes I get lucky and can set the pump trigger on the low setting and it'll fill ok not quick at all.

 

[IDIBRONCO]

This is definitely a mod I need to do with my 38 gallon rear tank. I feel bad being the guy taking forever to fill his truck. Sometimes I get lucky and can set the pump trigger on the low setting and it'll fill ok not quick at all.

It's definitely worth it to do this mod.

 

[ROCK HARVEY]

My fuel filling issues have been worse lately, and today I decided to check the rollover valve. I found out that the mud wasps/bees had plugged it completely. I thought I could just cut off the last few inches, but I kept finding bugs and dirt even 12” deep so I replaced the whole hose. I definitely recommend checking this!

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[franklin2]

A piece of window screen folded over the end and clamped with a wire tie or hose clamp will stop that. We have a terrible time with bugs and mice.

 

[Cubey]

This is definitely a mod I need to do with my 38 gallon rear tank. I feel bad being the guy taking forever to fill his truck. Sometimes I get lucky and can set the pump trigger on the low setting and it'll fill ok not quick at all.

The front tank on the RV was awful, especially if it was nose downhill, or a nozzle making a lot of foam. The filler was a LONG way from the tank, so it took extra time to get there if it having to go uphill or slowly go in as foam.

 

[snicklas]

One trick I seem to remember, that i haven’t seen in this thread, and could possibly help get until you can address the issue is:

Turn the fuel fill nozzle from the pump “upside down”. Have the hose from the pump pointing toward the sky, rather than the ground when filling. We’ve had a couple trucks that were hard to fill and this trick worked. You still could go wide open on the nozzle, but you could latch it and it would fill on it’s own.