Fuel Tank Vent

[LorenS]

I recently had my tank down to clean/install draw straw.  There was a vent-line looking connection that was plugged with crap, but nothing on the end of the line; I put a new piece of 5/16" fuel hose on it and made it into a loop to at least slow ingress of crap as the tank breathes.  Is there a special vent that's supposed to be there (like with a roll-over shutoff gizmo), or just a standard breather?  Or....?  Lots of things missing on my truck, including the puke bottle!  Didn't even know that was a thing until I saw MoparMan's PVC pipe trick.

[dripley]

The rollover thingy mabob is in the tank. The vent is just that fitting on the top of the fuel basket. I would think the added line would just catch more crap in its length than just the fitting, personal opinion. Mine has never clogged in 18+ years. Though the fuel basket is only 12 years old, could be different from OE.

[LorenS]

Thanks, Dripley, guess I'll just take off the hose!

[Dieselfuture]

This is my basket maybe it will help, last picture is how it stayed

 

[dripley]

I have the same in tank pump fuel basket.

[JAG1]

Dieselfuture, why do you have two fuel supplies? One is at 12:30, another at 3:00 positions? Then the smaller fuel return closer to the electrical connector? 

 

My tank vent hose I ran up higher near the fill neck to help keep road grim and chicken guts/ feathers from clogging the vent 

[Dieselfuture]

5 minutes ago, JAG1 said:

Dieselfuture, why do you have two fuel supplies? One is at 12:30, another at 3:00 positions? Then the smaller fuel return closer to the electrical connector? 

One is supply (plastic) corrugated, one is return (aluminum) from fass, both can be used as supply. You can actually see my abandoned drawstraw that po put in with a cap on it, he cut it too short and I had 1/4 tank losing fuel pressure issues, instead of getting new straw I got basket retrofit.  When I got my drawstraw5 it only came with one line and you were supposed to return fuel from fass or airdog to factory quick connect that acted as a supply originally. I had pressure that fluctuated up to 6 psi from restriction, after I up sized to 1/2" return it now only fluctuate 1-3psi depending on how hard I step on it. I later spoke with people that made drawstraw 5 and told them about my findings, they must of listened because within about a year they started to include two 1/2" lines one for supply and one for return. 

[dripley]

Mine is done the same way with an AD kit. Old pick up is now return for the pump and a new pickup. Both 3/8". I see mostly 4 psi drop sometimes 5. Might change them out one day. After retirement gets here.

[LorenS]

When I took my cage out to clean, the super fine mesh/strainer on the bottom of the cage came off, so now I REALLY have to make sure I have over a 1/4 tank of fuel so I don't suck air.  A replacement cage at RockAuto is $343 (Spectra SP7062M).  Anyone have experience with this and how to repair?  I don't know what kind of screen that is, or what glue would hold up.

 

I didn't think about it at the time, but it now seems weird that the draw straw with built-in return port just sprays the fuel back into the top of the tank instead of providing a means of returning it down low in the tank.  I bet my fuel is chock full of air when I get down below 1/2 tank!

[Dieselfuture]

The screen on bottom of basket comes of and stays off, I left mine off. Yes diesel fuel gets foamy if it's dumped on top. For that reason I ran my return as far down as I could inside the basket, I made a notch in the tube so fuel can still come out because it sits on bottom. 

If it gets dumped in fill line I think most bubbles come out before reaching fuel pick up and then fass/air dog removes the rest. Not sure on mechanical, must not be an issue. 

[LorenS]

The screen that was on the suction tube I left off, and am running a frame mounted coarse filter to catch big chunks.
However, there was a super fine screen/mesh on the very bottom of the fuel basket gizmo.  So fine I would expect that its purpose was to allow diesel into the basket, but too fine to let in water.  Now that all fuel in the basket can run out the bottom and into the tank, if I go downhill the fuel all runs to the front of the tank and away from the fuel pickup; there isn't a small reserve left in the basket!  Maybe I can mostly close off that opening with some very soft aluminum rivets and sheet material.

[Dieselfuture]

25 minutes ago, LorenS said:

So fine I would expect that its purpose was to allow diesel into the basket, but too fine to let in water.

No lol, keep that fine screen off the bottom, not sure on what you have on your intake tube for a screen,  unless you're talking about original intake pump sock.

If you know you'll be going off road it's a good idea to have more than half the tank just in case. I usually fill up when I get close to a 1/4 for many reasons. Sure if I'm on a long hwy trip I have got it down to almost nothing, knowing I had stations lined up when needed. Day to day, I fill up before I get low.

[Gregturley]

Leave the rubber hose on your vent. Make it long enough to get to easy and put a fuel filter for a carb'ed gas engine on the end. Allows it to breathe and the filter keeps out dust and crud. Easy to find in 5/16 and 3/8 and cheap. 

[LorenS]

4 hours ago, Dieselfuture said:

If you know you'll be going off road it's a good idea to have more than half the tank just in case.

I'm talking about an interstate exit ramp in an industrial area!  I sucked air and still had 6 gallons in the tank.  Somehow coasted to the diesel pump, had fun cracking injector lines so it'd start.

 

The intake sock is gone.  What I'm talking about is a super fine, blue-green material, fine like silk, that was glued to the bottom of the "sump" portion of the fuel basket; even from the factory I don't believe it's tight to the bottom, but held up 1/4 to 3/8" by the basket 'stand off'; I could be wrong about that.  I wish I'd taken photos!  Can't find a photo or video online showing what I mean.

1 hour ago, Gregturley said:

put a fuel filter for a carb'ed gas engine on the end

Good idea.

[Dieselfuture]

1 hour ago, LorenS said:

I wish I'd taken photos!

Yes it's hard to picture it but I'm pretty sure it's the fine screen that snaps over the whole bottom of basket, I took mine off and I'm able to suck the tank pretty empty, maybe few gallons left. The basket is spring loaded on my truck, so it always sits on the bottom, screen or no screen. I'm going of memory now crap.

Edited January 18, 2020 by Dieselfuture
Dumb phone

[dripley]

5 hours ago, Dieselfuture said:

Yes it's hard to picture it but I'm pretty sure it's the fine screen that snaps over the whole bottom of basket, I took mine off and I'm able to suck the tank pretty empty, maybe few gallons left. The basket is spring loaded on my truck, so it always sits on the bottom, screen or no screen. I'm going of memory now crap.

I dont remember any screen on the bottom of mine.

[Dieselfuture]

10 hours ago, dripley said:

I dont remember any screen on the bottom of mine.

I'll try to see if I kept them and take a picture