My rear gas tank no vent hose

[kat]

As you can see in picture, my rear tank doesn't seem to have a vent hose. As you can see it has the hose (far left small hose) but it isn't connected to tank and I can't see where it can be connected. The hose is connected to hard line that runs along frame, crosses over to passengers' side and then leads to nothing. After research it seems to suppose to have a charcoal cannister connected to it.
I've did a close inspection of tank and can't even see if the PO cut off nipple and filled it up. I don't know why anyone would do this.
My question is how do I fix this?? But a new tank? I do get a little blow back around rear tank gas tank lid.

 

[thegreatjustino]

The fill tube is the large hose at the bottom right, the vent tube is at the upper left. Marked in red on your photo below. If what I've labeled as the vent tube is routed somwehere other than the filler neck, something is routed incorrectly.

 

[kat]

The fill tube is the large hose at the bottom right, the vent tube is at the upper left. Marked in red on your photo below. If what I've labeled as the vent tube is routed somwehere other than the filler neck, something is routed incorrectly.

I agree with you. Maybe I labeled the hose wrong. But the little hose to the left that you didn't label just stops there and dosen't connect to tank like I think it should. I can't find the 'nipple' that I have seen on other tanks that are located to left of vent tube. Both the filler hose and vent tube are connected.

 

[thegreatjustino]

If this is the '76 in your signature, it would have had a full evaporative return system from the factory. Lines to the charcoal canister as well as the vapor recovery tank behind the panel in the quarter panel behind the driver seat. Is the plastic tank with evap lines going to it still in the quarter panel behind the screwed on panel (right behind the driver seat)?

 

[kat]

If this is the '76 in your signature, it would have had a full evaporative return system from the factory. Lines to the charcoal canister as well as the vapor recovery tank behind the panel in the quarter panel behind the driver seat. Is the plastic tank with evap lines going to it still in the quarter panel behind the screwed on panel (right behind the driver seat)?

It is a '76 and as I stated in my first post, that hose that small hose on the far left runs into a hard line and goes along frame then goes to the passenger's side to a NON existing canister. Below is a picture of where it ends up. There is nothing behind driver's seat. I do have auxiliary tank if that means anything. I believe '76 had a plastic tank that hangs under hood on firewall. There is a on firewall that looks like where it should be. But the hard line tells me it goes to a charcoal cannister mounted somewhere on frame.

 

[thegreatjustino]

Here's a thread with the evap lines & related canisters.

Gas Tank Pressure, Evap System, and Gas Caps?

So, Someone gutted the EVAP system on my 71. I put on a vented gas cap when I installed my new tank. With the new tank, I notice a "whoosh" every time I open the cap. The tank is pressurized from the heat and vapor. I guess the old tank had a leak, because it didn't do this. So, I have...

classicbroncos.com

 

[kat]

Here's a thread with the evap lines & related canisters.

Gas Tank Pressure, Evap System, and Gas Caps?

So, Someone gutted the EVAP system on my 71. I put on a vented gas cap when I installed my new tank. With the new tank, I notice a "whoosh" every time I open the cap. The tank is pressurized from the heat and vapor. I guess the old tank had a leak, because it didn't do this. So, I have...

classicbroncos.com

Thanks for the help but that thread doesn't tell me anything about the non existing vent hose for gas tank. The pics doesn't show up in thread. I'm assuming I need to get a new tank, but just weird that this tank has no vent (not overflow) holes

 

[thegreatjustino]

The pics doesn't show up in thread.

Post #3 in the thread shows all the diagrams. Figure out what you're missing and replace as needed. If your tank doesn't have the two quarter inch nipples, someone replaced the stock '76 tank with an earlier one from a year that didn't have the evap system. Does your auxiliary tank have the nipple for the quarter inch evap line?

 

[mrdrnac]

Early Bronco Auxiliary tanks didn't have the small vent on them, just the fill and the large vent hose to the filler tube. So you probably have an early auxiliary tank on a later Bronco, I think they added the vent in 71-77 and 66 to 70 didn't have it.?

 

[kat]

Post #3 in the thread shows all the diagrams. Figure out what you're missing and replace as needed. If your tank doesn't have the two quarter inch nipples, someone replaced the stock '76 tank with an earlier one from a year that didn't have the evap system. Does your auxiliary tank have the nipple for the quarter inch evap line?

Diagrams doesn't show up for me. But I think you answered my question. The OP did some questionable things so having the wrong year rear tank is probably what happened. Because you can tell in the my pictrue that there isn't a nipple on the tank where the line goes. I didn't realize they changed style of tanks. When I got it the Aux tank was busted so purchased new '76 Aux tank and it vents fine. I want to get rid of hard lines on frame. I'm sure there is a simpler solution than the charcoal cannister.

 

[kat]

After looking at new rear fuel tanks for my 76 I noticed not only does my fuel tank not have the vent nipples that show up in pictures, but also 'overflow' hose is on the wrong side of the fill hose. Even a new filler neck shows the overflow tube towards the back of Bronco. Mine is definitely towards the front of Bronco. WTF? Can someone explain?

 

[DirtDonk]

I saw that as well last night but was going to go look to make sure I was not just remembering wrong.
Also, the '76 was a transition year between the early '70 to '76 style round metal charcoal canister mounted to the frame, along with condensing tank behind the driver's shoulder, to the later '76-'77 plastic charcoal canister mounted to the firewall and no tank behind the driver.
I say it's a swapped-in tank too, but I have never looked at a '76 tank in depth either.

Your single hard line shaped as it is in your picture looks to me like it was a later style. Your mention of a bracket(?) on the firewall kind of follows that thinking.
Is there a metal panel in the notch in front of the rear wheel well on the driver's side in the cab? Is there a rubber grommet in the oval shaped hole just visible from the front of the rear wheel opening?
If there is a grommet, is it solid and sealed? Or is it punched with a few holes in it?
I think later '77's had that hole left out and was solid metal, but I think early ones with the new system simply got a rubber or plastic snap-in plug.

Evap came on Broncos in at least CA (but I think it was all 50 states at that point) sometime in mid-'70 model year. The aux tanks got the single small vent nipple and the main tanks got two. The fill-vents appeared some time before that I believe, but don't remember all the discussions we had years ago that helped to narrow down the range of when the fill-vent started to appear on the aux tanks.
My '71 had it originally, but the front tank in my '68 is long gone and I never saw it.

Got any pics of the area behind the driver's left shoulder?
Got any pics of that area under the vehicle as viewed from the wheel well?
Any chance you can clean up the tank a bit more and look for any slight clue to there ever being a fitting?

An early evap system would have included two fittings on the tank. A later one would have had only one, or two with one plugged/capped/closed.
Maybe some of the members here with '76's and stock tanks can post up some pics of their tank venting and their charcoal canister setups.

Paul

 

[Oldtimer]

1968 factory AUX tank had NO vent hose provision.
Well, except for the holes in the top of it, from when the dealer drilled drain holes in the floor pan per a TSB.

 

[kat]

I saw that as well last night but was going to go look to make sure I was not just remembering wrong.
Also, the '76 was a transition year between the early '70 to '76 style round metal charcoal canister mounted to the frame, along with condensing tank behind the driver's shoulder, to the later '76-'77 plastic charcoal canister mounted to the firewall and no tank behind the driver.
I say it's a swapped-in tank too, but I have never looked at a '76 tank in depth either.

Your single hard line shaped as it is in your picture looks to me like it was a later style. Your mention of a bracket(?) on the firewall kind of follows that thinking.
Is there a metal panel in the notch in front of the rear wheel well on the driver's side in the cab? Is there a rubber grommet in the oval shaped hole just visible from the front of the rear wheel opening?
If there is a grommet, is it solid and sealed? Or is it punched with a few holes in it?
I think later '77's had that hole left out and was solid metal, but I think early ones with the new system simply got a rubber or plastic snap-in plug.

Evap came on Broncos in at least CA (but I think it was all 50 states at that point) sometime in mid-'70 model year. The aux tanks got the single small vent nipple and the main tanks got two. The fill-vents appeared some time before that I believe, but don't remember all the discussions we had years ago that helped to narrow down the range of when the fill-vent started to appear on the aux tanks.
My '71 had it originally, but the front tank in my '68 is long gone and I never saw it.

Got any pics of the area behind the driver's left shoulder?
Got any pics of that area under the vehicle as viewed from the wheel well?
Any chance you can clean up the tank a bit more and look for any slight clue to there ever being a fitting?

An early evap system would have included two fittings on the tank. A later one would have had only one, or two with one plugged/capped/closed.
Maybe some of the members here with '76's and stock tanks can post up some pics of their tank venting and their charcoal canister setups.

Paul

Thanks for the info Paul, if you scroll up on this thread you will see a pic I took on passengers side wheel well where the hard line comes out. I have nothing behind drivers left shoulder. I'll have to look closer this weekend and take some pictures if need be of firewall. But I do remember a flange type thing of firewall on passengers side I do believe. (Not 100% sure). I'll double check on welded up nipples on gas tank but don't think there is nothing there. How is my fill tube on the opposite side of overflow tube according to pictures of new tanks?

 

[tirewater]

Here are some photos of my '76.

 

[kat]

Here are some photos of my '76.

Very helpful, thank you. The plumbing under Bronco is like mine except for the hard line that stops under passengers side fender well. But your tank connections are different than mine. I'm going to try to take a picture of where your plastic tank is located because that is where I have the 'hanger' thingy on firewall.

 

[tirewater]

The photos are showing up out of order. The first is obviously the fuel tank (a stock reproduction). The second picture is the evap hard line crossing from driver side to passenger side.

The third/fourth photos are driver side, before the hard line that cross the body, they should be before the 2nd pic. You can see the rubber grommet that goes into the cabin - which I suppose was for the behind the seat EVAP can in earlier models?

The charcoal canister is last. It's screwed into the firewall flange by a single sheet metal screw.

 

[kat]

First pic is a closer shot of side of rear gas tank. It does appear that maybe the PO did some welding or putty. There is some sketchy things around the overflow neck (which is on the wrong side). Hopefully after the rain I can clean it up better and get a better look, but I will most likely buying a new tank.

Second pic is that 'hangy' thing that the plastic tank should hook to.

While I have your attention, would there be anything wrong with getting rid of all that evap plumbing? Not planning on selling so don't care about being original. Also, no vehicle inspection in FLA.

 

[DirtDonk]

For me, the evap stuff has nothing to do with legal emissions, certification in certain areas, or originality. It’s all about clean air and being able to park it in the garage.
Some people get away without it, and don’t have the gas fumes. Most don’t…

 

[DirtDonk]

Wrong filler neck? Wrong tank? Well, maybe.
Or maybe not.
Maybe it was just a transitional thing where Ford made a change.

Just out of curiosity, what month was your bronco built in?