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73strokin 11-25-2008 06:09 PM

Fuel Filler Neck Mod Variations
What is the better way to do this mod, by reinstalling the tank vent/rollover valve in the new tube or just leave it out of the system? I've seen writeups doing it both ways and some people say that the filler cap will vent the tank so the valve isn't needed, but if the cap doesn't vent I see how it might be a good idea to reinstall the valve. Any suggestions?

plowhand 11-25-2008 06:29 PM

The rollover valve is vented seperate from the tank filler neck, via a small (1/4" I think) rubber hose that clips to the frame. When I did my filler neck mod I left the rollover valve inplace (removed and cleaned of course).

tjbeggs 11-25-2008 07:58 PM

I left the roll over valve out and used the hole for the base end of the vent hose. I guess I can't say one way is better than the other.

wildstang 11-26-2008 05:20 AM

What does this mod accomplish? Does it allow a quicker fill up? I fill mine up so that the fuel is almost touching the cap but it takes a while because I need to drizzel it in because it will foam a lot. Probably makes the fill up twice as long. Thanks

tjbeggs 11-26-2008 06:40 AM

Yes it allows faster fills and also allows you to pull up to any pump to fill. The OTR truck pumps have nozzles that are about twice the size of a standard nozzle and they don't fit our filler neck without doing this mod.

DZL JIM 11-26-2008 07:10 AM

I would not want to get rid of the roll-over valve. It's there for a reason, in the event you, well, roll over, it will keep your #2 where it's supposed to be and not create a hazard.

Not sure what write-ups you've seen, but there is a larger valve available from Ford that has a larger barb on the end of it. Get one of these larger valves and run your hose from the valve to the top of the filler neck by the filler cap. It vents fine and you still have the roll-over protection.

I show part number #F4TZ-9B593-H for the larger valve, but I'm not 100% sure that's it. Maybe go to Ford and see for yourself, if it has the large barb on the end and not a small 1/4 barb, then that's the one. You might also need a new grommet, I show #F6TZ-9B076-AA for that.

Good luck.

wildstang 11-26-2008 08:16 AM

I'm lazy, does anyone have a link to the write up? How long does it take to do? Leaving in the roll over valve in but doing the mod, are fill ups still faster or is the roll over valve what slows it down?

DZL JIM 11-26-2008 12:47 PM

Here's one: Vent mod.

Ripping the guts out of the filler hose and adding the external hose is what makes it fill faster.
Leaving the roll-over valve in there is just for safety precaution in the event of an accident.

73strokin 11-26-2008 04:50 PM

Well, as I understand it, this mod involves gutting the filler neck as well as plumbing the line from the top of the tank (where to vent valve is) into the filler neck. So, even without the vent valve included in the mod, fuel would just flow in a closed loop through the hose, into the filler neck, and back into the tank, correct? (In the event of a rollover) My main question is regaurding if the valve has to be reinstalled to allow the tank to breath, or will the filler cap naturally vent by itself to prevent a pressure/vacuum in the tank?

plowhand 11-26-2008 05:59 PM

After re-reading my earlier post I found that it lacked alot of info, sorry 5 yr. old grandson needed someone to play with last night.

So maybe this will be better. When I did my mod I put the 90 degree hose bard in the tank where the rollover valve was, ran 3/4" hose up to the frame, cut the hose, put a "T" hose barb in, continued the hose to the bard welded to the top of the filler neck. Then I put a short piece of 3/4" hose on the "T" barb and then put the rollover valve in the short piece of hose (zip tied the rollover valve to the frame) and then ran the vent tube from the rollover valve up to the frame and clipped it on.

This way the fuel going into the tank can push air out from where the rollover valve was on the tank up the 3/4" hose to the top of the filler neck (which is above the bottom of the fuel nozzle) and out. With the fuel cap on the tank can breath through the rollover valve which is installed in the 3/4" hose. Hope this makes more sense.

compaddict 11-27-2008 11:32 PM

I would pay someone to do this to my truck...


BlueMule 11-28-2008 12:20 AM

Originally Posted by compaddict (Post 6819994)
I would pay someone to do this to my truck...


well bring it over on Saturday morning }>

compaddict 11-28-2008 10:09 AM



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