I did the fuel tank vent mod today (love it already). When I had the tank dropped, I noticed two hose barbs on the top of the tank with nothing connected to them. I took a piece of fuel line and connected the two together. Is that OK? What are they for anyway and why in the heck are they open on the top of the tank? Seems to me if you did some deep-water crossings, you could possibly get some water in the fuel tank.

 

Back up to the top

 

Good on ya pal for doing you fuel system a favor. Those vents are used on the gas application for the emissions control. Since we share the same tank mother mopar saved a buck and didn't bother supplying hoses. I found the same thing and joined the two vents into a tee and ran a third line up into a loop at the filler next. The biggest problem with these vents is the elbow sits in a moulded depression that can and will collect road grime. When your fuel cools off (contracts) they will suck in the crud. Say when you did the mod how did the inside of your tank look. Not long after I had mine I dropped the tank and cleaned it out. Too much crud for my liking. I've got to email Kelly and get the vent mod done this spring. Wife won't let me fillup when she's along for the ride..big scene

 

I joined the two of mine with a 't' fitting and then ran a line up near the top of the fuel filler and zip tied a cheap fuel filter so that all air is filtered and if I'm that deep in water I'll have other things to be worried about. I didn't just cap them or join the two together because as fuel is depleted there will be a vacuum created in the tank due to no vent and this could cause extra strain on the lift pump. I'll try and post some pictures of my final product if I can get some pics this weekend.

 

I have the vent mod. I did nothing with those hose barbs. I know alot of you guys are worried about something getting into them, but as far as I can tell, nothing should happen.
When we fill up to the neck with fuel, why doesn't/wouldn't fuel spit out of these barbs? There is fuel above them, afterall.... Should be pressure to push fuel out, but it doesn't. What do you guys think?

 

Hey Trik396, they reason fuel doesn't come out is because they have rollover valves built in...esssentially a float valve that when fuel pushes up on the float it forces the valve to close. That is why if you fill to the top you won't see fuel come out the vents. Just humour me and go out to your truck with 3ft or so of 3/8 hose when the truck is 1/2 full, put it on one of the fittings and try to suck and blow on the hose...guaranteed you will have air flow in both directions. Kinda scary really when you consider how many warranty claims DC has denied due to dirty fuel or contamination in tank! You won't have to drop the tank again to rig up something (I didn't). Like I said humour me and let me know what you find. I have been told some short boxes don't have the fittings in a 'valley' like the long box tanks but apparently still flow in both directions unless the tank is full. There are some pics in my gallery from before I did my permanent fix, just a quick fix of install some hose to get the fittings openings out of the gunk collecting 'valley'.

 

I didn't know about the rollover valves, but that certainly makes sense. I won't have to humor you. I'm just gonna install some hose with a filter and tee setup as explained.... as long as I don't have to drop that friggin tank again....
btw- what size hose did you use?

 

I used 3/8" fuel rated hose. I was able to get at both fittings from underneath without dropping anything. Some have used a clear plastic fuel filter for late 60's VW bugs. I went to my local parts store and just started opening boxes until I found what I wanted. I got a filter that is semi-transparent (housing) and has 2 fittings on top of it, I figured this way if any water (mist or more) got into the fitting it will settle out to the bottom of the filter instead of going into the the vent hose. Either way at he very least a filter is a good idea so that any air going into the tank is filtered of dust and water.

 

Very cool... Thanks

 

I used .250 (1/4) on mine, that is what the barb measured with my caliper. I will go get a T and run it up. Thanks!!!!!!

 

Oh Crap! I think you might be right OOPS! I think it may have been 1/4" I used. I have 2 sizes on the shelf here at work and I think it was the smaller of the 2 since you mentioned it which is 1/4".

Sorry trik396! I may have misled you! I will try to confirm tonight what I actually put on the truck but I think it was 1/4".