Fuel Expansion Tank Question

Hey all - me again...

Got done my lift, drove it for a day, parked the jeep and found a nice puddle of gas under the rig. Ended up dropping the tank (not fun) to find that the main feed line was totally old, cracked, and mangled. In the process I also discovered that a lot of the vent lines going to the expansion canister are also need of replacing. One of the corner nipples actually broke off as well (I assume it was already failing given how it looks -and seems like someone tried to repair it at one point).

Anyways - I think keeping the expansion tank is the right idea so I don't always smell like gas (ha), but I'm curious if I should need to replace this broken vent or if capping it on the gas tank and running just 3 to the expansion tank will work? If I do need to repair it, I'm thinking some JB tank putty should do the trick but I'm open to other suggestions.

Considered replacing the tank now, but I'm not sold on which configuration I'd go with so I'm most likely going to do the simple fuel line work, verify my sending unit is ok (turns out it wasn't even plugged in...), and popping the tank back in for now - if/when something else happens I'll go with a full new tank and possibly a floatless sending unit.

 

I know dropping the rear tank in these CJs is a real b1tch! Installing them isn't much easier.
Make darn sure you have everything restored or replaced prior to going back up with the tank.
To me, a new tank and sending unit is a no-brainer.
My evaporative canister was gone when I bought my '71 in 2006. I never replaced it. I did replace the tank and capped off the evaporative lines. Yes, it smells like fuel a couple days after I drive it (carb fumes), but I just live with it.

 

Cap the lines and insure you have a vented cap. Most rear tanks have little to no smell if all the lines are solid. You might get a few fumes from the carb, but, with all the firewall holes plugged, that should be minimal as well.

 

So with those replies it seems that one less vent won’t cause much issue? Thinking a bolt and o ring to plug the busted hole is the way to go. It sure it tight trying to get all of those fuel lines nested pretty when lifting the tank back up….

 

If you are reusing your old tank, make sure it's cleaned well inside! Test the sending unit through its entire stroke also.
This has been covered at this site previously.

 

I installed an empty 16oz. propane canister as an expansion tank where the tip over valve was. I took the valve out of the top and replaced it with a filter. Tapped a hole in the bottom for gas in. Welded a couple studs on the side and plumbed to my tanks. I did this after installing an under seat tank. Every time i stopped on a side hill I was dumping gas out the filler. Now I can run non vented caps and spill or smell no gas. To cap off unused lines I use a piece of fuel line install it on the tank. Cut it and plug the line with a non threaded bolt and hose clamp.

 

I was looking at something similar for mine. I'll likely put it high in the driver side rear corner so it can drain back to the tank and also keep the vent above water level.

 

That is where my tank is. No more gas smell or spilling on either tank.

 

Make sure you use a viton o-ring. Buna-N doesn't really do well with gasoline. That said, I don't think just threading a bolt in there with no nut on the back side is going to hold long term. I would be inclined to just purge the tank with CO2 and weld that shut.

 

Good call - I'm going to run it as is now with the bolt and O ring and if either fails I'll come up with another plan.

I did break another breather nipple off and added a 90 deg flared nipple to keep my vent working on that corner, so i do have a good plan to repurpose the hole if I need to and just run the vent with a soft line instead of the hard line (which catches on everything). Either way, Jeep seems to run fine now and no gas smell to report.

 

Don't want to hijack @gnardoggie 's thread but I could use some help with venting a tank on a Wagon. My tank is an aftermarket and has a Fitech in-tank pump system. It has a built in vent that's currently plugged. I'm using a vented cap but all the vented caps I've found have a one way vent in, not out. Would love to find a 2 way vented cap; anybody?
Also if there's more info on installing an aftermarket vent canister, would really appreciate some direction.

 

Does your tank have any built in vent nipples?

 

Yes, a single. And it being a Wagon, there could be some more options for mounting some sort of canister(?)

 

you could just toss a fuel tank vent on it and see if that helps - it might smell but it'll vent! https://www.summitracing.com/parts/...wPEz1TszMVzHMDTTCX5dOiWadlGwwtPRoC0cwQAvD_BwE


https://www.classicperformancerestoration.com/product-page/charcoal-vapor-trapper

 

hey yall - me again. So I went to fill my tank fully since redoing everything and the expansion tank started spewing fuel everywhere. It seems like the "limit fill valve hose" wasn't actually connected to anything. For some reason my expansion tank was then filling with fuel and pushing it out that line.

Any idea why should be connected to the end of that? I'm curious how this didn't happen before - maybe I changed around the tube routing somehow or something?

 

My expansion tank has two inlets at the bottom one coming from each tank with non venting caps. The outlet has a small filter on it on the very top. The tank is mounted as high as possible behind the drivers rear tire.

If you are having gas pushed out through the expansion tank your main vent that returns vapors back where you insert the fill nozzle may blocked.
With the vapor recovery pumps we have here don't let it seal on the tank.

Hope this helps.

 

I've got the 5 nipple expansion tank (one line from each tank corner, and one line that should run under the hood) but the concept you mention should be the same. Why would the filler vent cause gas to push above the height of the main gas tank itself?

 

You only need one vent for filling and one to vent the tank when the cap is on. Plug he rest especially the one next to the fill spout. There is possibly a baffle there causing your problem.
What your is your jeep?