Charcoal Canister / EVAP Install / Solve Gas Smell

[CopperBronco]

I decided to write this up, because it was so hard to find. And I know most of you hate charcoal canisters and EVAP/DEQ crap on your Broncos, but for me the gasoline smell was so potent it was fumigating my house and my small children. This isn't acceptable of course. I'm new to Broncos, so any of the above could be wrong, but I did my best. Open to any and all comments here if I got anything wrong I'm running a 66ish Bronco (restored), 2Brl Carb, on a 302 V8. Obviously the install will be different for those with other setups. Hope this helps anyone trying to do this as installing it is easy, finding the parts and right info was not for a newbie like me.

A couple of quick hacks that can work without the hassle of EVAP system:

– don't fill up your gas tank all the way, only 3/4 to give room for vapor to expand inside your tank if it isn't vented properly
– you can just vent your two vent holes on the stock 13 gallon tank to each other with some rubber hose to close them off, use fuel injection clamps for a tight seal (Thanks to Andrew @Baja Broncos for this tip & the first one when I was selling him some parts, check out his awesome Stroppe Broncos).
– obviously if you have bad gas smell check for leaks, especially along fill/vent hoses, and check your gas caps as well if they're vented or not
– avoid spring clamps and go with fuel injection clamps all around for venting, my mechanic said they seal up way better (not sure if true)

Now as for installing / retro-fitting a charcoal canister and vent lines on your Bronco, getting all the parts can be quite the hunt as their are not entire kits out there, so you'll have to source from multiple suppliers:

LMR – for 80's ford Charcoal Canister Kit – '87-93 mustang (this is what I used)
https://lmr.com/item/LRS-9653BK/mustang-charcoal-canister-restoration-kit-8793
This is installed to your passenger or driver's side firewall pending your Bronco setup, you need to install this at the highest point possible to avoid fuel getting into it, so you want it well above your gas tanks. You can install the Bronco original condensation / overflow tank that sits behind the driver's side door in the later 70's Broncos, but I was told my guys at Tom's Bronco that you want to avoid this, as the parts are super hard to find, and also it was a poor design. No matter what the 4 hoses and fittings into that tank always would break/crack, and leak gas fumes into your cab. It also wasn't the easiest to access. Ford later moved these overflow vapor tanks away from here due to the poor design. The LMR kit is a little confusing with the 4 holes, my understanding is you put a cap (part link below) onto the one nearest the two small holes, then large hole vents from the canister to your air cleaner, and the two small holes are for gas tank intake and purge valve connections. I capped the purge valve connection as my Bronco doesn't have a computer on board like the newer Mustangs did back then.

Sadly these canisters above don't come with the caps, they can be found here, super expensive for a little piece of plastic. Only ordered 1 since it looks like you're supposed to vent the other large hole to your air cleaner. Per Paul's note below, these don't seal the canister, but prevent things from getting in. For certain setups you'll need two of these.
https://www.ebay.com/p/1311225085?iid=255029656081
Ford part number D1AZ-9E602-B

If you want original stock OEM canister go the Mercury Cougar Parts catalog here in Oregon, sometimes these have to be baked to restore I'm told:
https://secure.cougarpartscatalog.com/1919mecofomu2.html – they have brackets and original charcoal canisters that match the Bronco from what I can tell, not sure how well these work, but I'm sure they do.

For the charcoal canister to air cleaner (as the air cleaner will suck in the fuel vapors and recycle them into your engine), go here for a vintage mustang charcoal canister to air cleaner hose:
https://www.mustangsetc.com/3-4-air-cleaner-to-charcoal-canister-fuel-vapor-hose/ – or go find any old aluminum hose, even HVAC ones can work I'm told, this is a 3/4 hose at Mustangs etc... the 3/4 hose was a little big, but I put a sleeve in side it and then clamped it onto the air cleaner intake port. I'm connecting one of the large openings on the charcoal canister

It's also wise to install a rollover valve between the gas tanks & the charcoal canister to prevent fuel from getting into the charcoal canister in case of a heavy nose dive situation, like a steep downhill slope, or a rollover accident. I found this one: https://store.delorean.com/101402-rollover-valve.html , as it looked simplest to hook up and matched my fuel line sizes on my stock aux and main tanks, but any check valve or rollover valve could work. I installed this rollover valve above my passenger side frame rail to a clip in the tub of my Bronco, I have a 3" body lift so it causes the vapor line to raise up quite a bit, and then drops back down as I zip tied the vapor lines to the frame as it travels up to the passenger firewall.

Obviously you'll need a lot of fuel hose line and fuel injection clamps to connect your fuel tank vents from your main and auxiliary tanks all the way to the charcoal canister. Original Ford motor diagrams for EVAP are attached here as well just for Stock/OEM reference. This helped me figure out how to create my own system and follow as closely as I thought I should. I also drew a basic diagram of what I did from my tanks.

Here are additional threads on this topic on ClassicBroncos, they are often incomplete and hard to find, thought I'd put this all in one place for folks if the gas smell is ruining your wife or children's lives.

https://classicbroncos.com/forums/threads/charcoal-canister.313882/#post-3415668
https://classicbroncos.com/forums/threads/mustang-efi-charcoal-canister.313673/#post-3412855
https://classicbroncos.com/forums/threads/charcoal-canister-installation.261451/
https://classicbroncos.com/forums/threads/where-should-the-charcoal-canister-be-mounted.218039/
https://classicbroncos.com/forums/threads/gas-tank-pressure-evap-system-and-gas-caps.310185/
https://classicbroncos.com/forums/threads/plastic-bottle-under-panel-behind-drivers-seat.86497/

 

[DirtDonk]

A lot of information! Thanks for putting it all together.
A couple of extra details.

Those “caps“ are actually vented so they are not to seal off the opening but simply to keep debris out while letting air in to allow better flow through the canister to the air cleaner.
Vehicles with the purge valve controlled by the computer and pulled by vacuum will actually use two of those caps for venting.

The condensing tank on earlier models was actually kind of a clever way to keep liquid out of the charcoal canister. But it did have its faults as you pointed out.
It was changed in ‘76 however, not because Ford thought the old was such a bad idea, so much as to meet the upcoming regulations for ‘77 to get all possible fuel vapors out of the cabin. So all in cab gas tanks and vapor tanks were moved to the outside.
So I guess you could really say it was a bad idea. Because gasoline storage in the passenger compartment was actually kind of a bad idea from the beginning. But all of them did it anyway!

And even fuel injected engine suffer the same fate. The vapors come from both the fuel usage and from the fuel storage. So the evaporative emissions system is still in play with fuel injection.

Retrofitting a 66 to 70 model year bronco with evaporative emissions, or Re-fitting later ones where it was removed is a very good upgrade in my opinion. We should all do it.

Thanks again for putting it together.

Paul

 

[DirtDonk]

Forgot to mention that it is more difficult on pre-70 models because of the lack of vent tubes coming out of most of the gas tanks. But it’s still a viable upgrade if you can do the extra work.

And because those earlier models had vented gas caps the upgrade is not truly complete until you also update the filler neck and gas cap to the post 70 model design.
If you already mentioned that, sorry for the repeat. But it’s not bad to focus on some of the small details.

Paul

 

[CopperBronco]

Thanks Paul! I knew someone like you would fill the gaps. Yes, mine has updated filler necks and gas caps already, probably should have mentioned that.

 

[MarsChariot]

Another discussion to add to the "additional threads", from many years ago: https://classicbroncos.com/forums/threads/plastic-bottle-under-panel-behind-drivers-seat.86497/

 

[73azbronco]

Point to ponder, your fuel vent lines do not need efi style fuel claps, standard screw on hose clamps or even the spring ones work.

 

[CopperBronco]

Another discussion to add to the "additional threads", from many years ago: https://classicbroncos.com/forums/threads/plastic-bottle-under-panel-behind-drivers-seat.86497/

Thanks added to list above!

 

[CopperBronco]

Point to ponder, your fuel vent lines do not need efi style fuel claps, standard screw on hose clamps or even the spring ones work.

Agreed, but I prefer overkill, and in case of overfilling the gas tanks, which I had someone do at a gas station one day while they were not paying attention, as I live in Oregon and can't fill my own gas, I didn't have any leaks. even though the lines were most likely full of gas.

 

[VintageBronco4563]

You may consider purchasing an aftermarket charcoal filter such as the following: https://www.classicperformanceresto...l-canister-fits-all-vehicles-with-a-fuel-tank

We've used said filter on numerous customer Bronco's that made the work area smell absolutely terrible. Highly recommend, they work quite well at eliminating gasoline smell.

 

[DirtDonk]

Interesting. Thanks for posting it up.
Is it basically just a more straight flow-through canister made to be mounted in alternate locations? Does it still connect to the air cleaner at the other end? Or is it designed to be a stand-alone with the output just vented to atmosphere?
Guessing from tank to air cleaner, to better keep the remaining fumes out of the garage. Looks like it can be mounted vertically or horizontally.

Probably opens up some new potential mounting locations and definitely looks cooler. And being able to renew the charcoal medium isn't a bad thing either.
I guess for most of us a 40 dollar version will still have more appeal than a 225 dollar version. But that coming from someone still thinking about buying a $200 PCV valve!
Looks like a nice alternative to the garden variety kind.

Paul

 

[m_m70]

But that coming from someone still thinking about buying a $200 PCV valve!

wait, what?? whoa.......

 

[DirtDonk]

Yep. Fancy new adjustable one for those odd applications.
Probably won't need it for my 302's since they're very close to stock, but the 400 is theoretically outside of those normal bounds so thinking about that fancy billet adjustable one for that application.
We had a thread going on about it a year or two ago somewhere around here.

Paul

 

[fountain4ever]

You may consider purchasing an aftermarket charcoal filter such as the following: https://www.classicperformanceresto...l-canister-fits-all-vehicles-with-a-fuel-tank

We've used said filter on numerous customer Bronco's that made the work area smell absolutely terrible. Highly recommend, they work quite well at eliminating gasoline smell.

We have used their filter as well. I think they call it the Vapor Trapper. We have a 67 Bronco with a Coyote 5.0. The fuel cell vent line was large and it had a horrible raw fuel smell. When we added their charcoal canister - it virtually took all the gas smell away!

 

[fountain4ever]

Interesting. Thanks for posting it up.
Is it basically just a more straight flow-through canister made to be mounted in alternate locations? Does it still connect to the air cleaner at the other end? Or is it designed to be a stand-alone with the output just vented to atmosphere?
Guessing from tank to air cleaner, to better keep the remaining fumes out of the garage. Looks like it can be mounted vertically or horizontally.

Probably opens up some new potential mounting locations and definitely looks cooler. And being able to renew the charcoal medium isn't a bad thing either.
I guess for most of us a 40 dollar version will still have more appeal than a 225 dollar version. But that coming from someone still thinking about buying a $200 PCV valve!
Looks like a nice alternative to the garden variety kind.

Paul

This nice thing about the Vapor trapper is the versatility of it and how/where to mount it. We have mounted it in the back by the Fuel cell off the vent line directly from the Fuel cell where it vents to atmosphere - with great results on a couple different vehicles. I would agree putting it in line back to the Carburetor/air cleaner is also a great idea. It is more pricey then the plastic retrofit parts, but it is really a high quality part and plus, it is rechargeable. It can have new media installed so it is a forever part versus trying to refit aftermarket parts every 5 years hoping to find the same one. Anyway, we have had great luck with it plus it is a great looking part! Just another alternative to solve some of these issues! Good luck!

 

[dmplatt]

Thanks for this thread and all the links. I'm dealing with a bad venting issue which I think is coming from the rear tank when it's more full than not (23gal NWMP). So if I am understanding correctly, I can eliminate the bottle from in the cab by adding a firewall mounted canister and a check valve. Just re-route everything out of of the cab and go straight to the engine compartment - and there is no need to even have the bottle at that point right, it's a delete not a relocate? Seems pretty straight forward... Then I need to figure out which other hoses (fill, etc...) may be leaking vapors!

But this won't solve the problem of my clothes smelling like raw gas after driving right? That seems to be related to fuel usage and not storage so a different problem altogether?

 

[guidoverduci]

Subscribing here. I’ve got the NWMP tank as well. My fuel tank just vents straight to the air cleaner and I don’t have any issues with fumes. Not a fan of that setup, always looking for new ideas.

 

[DirtDonk]

If the cab smells strongly of gas after a fillup, it's likely that your condensing tank inside the cabin is split at the seam and leaking.
You can fix that directly by sealing up the leak, or yes you can eliminate it altogether as this discussion has mentioned.

I sealed mine up with some good old Form-a-Gasket #1 or #2, but in my opinion the better method overall is to eliminate it altogether and mount a new canister (type of your choosing) up high on the firewall.
And yes, it should completely eliminate the smell of gas from your clothes!

In fact, just the fact that you're getting that much into the cabin says to me that your condensing tank is leaking. Either that, or you have a very serious leak at the top of your gas tank under the truck, and the fumes are just getting into the cabin through all the usual holes in the floor, wheel wells, seams, vents and cracks typically found in Broncos.
Would not hurt to check your main tank up top for seepage (a bright flashlight usually tells the tale) but it's never really a bad idea to eliminate gas in the cab no matter what the issue.
This is exactly why they were outlawed in '77 by the gummint.

Paul

 

[dmplatt]

Yeah, I'm pretty certain it's a rear tank issue, last time I had eyes the condensing tank (when taking off the top) it was all intact and I've had previous issues with the rear tank venting... I've never dropped either tank but it sounds like that's in my future. But since it's way easier to check the condensing tank I'll definitely doo that first

 

[Bronco_007]

I decided to write this up, because it was so hard to find. And I know most of you hate charcoal canisters and EVAP/DEQ crap on your Broncos, but for me the gasoline smell was so potent it was fumigating my house and my small children. This isn't acceptable of course. I'm new to Broncos, so any of the above could be wrong, but I did my best. Open to any and all comments here if I got anything wrong I'm running a 66ish Bronco (restored), 2Brl Carb, on a 302 V8. Obviously the install will be different for those with other setups. Hope this helps anyone trying to do this as installing it is easy, finding the parts and right info was not for a newbie like me.

A couple of quick hacks that can work without the hassle of EVAP system:

– don't fill up your gas tank all the way, only 3/4 to give room for vapor to expand inside your tank if it isn't vented properly
– you can just vent your two vent holes on the stock 13 gallon tank to each other with some rubber hose to close them off, use fuel injection clamps for a tight seal (Thanks to Andrew @Baja Broncos for this tip & the first one when I was selling him some parts, check out his awesome Stroppe Broncos).
– obviously if you have bad gas smell check for leaks, especially along fill/vent hoses, and check your gas caps as well if they're vented or not
– avoid spring clamps and go with fuel injection clamps all around for venting, my mechanic said they seal up way better (not sure if true)

Now as for installing / retro-fitting a charcoal canister and vent lines on your Bronco, getting all the parts can be quite the hunt as their are not entire kits out there, so you'll have to source from multiple suppliers:

LMR – for 80's ford Charcoal Canister Kit – '87-93 mustang (this is what I used)
https://lmr.com/item/LRS-9653BK/mustang-charcoal-canister-restoration-kit-8793
This is installed to your passenger or driver's side firewall pending your Bronco setup, you need to install this at the highest point possible to avoid fuel getting into it, so you want it well above your gas tanks. You can install the Bronco original condensation / overflow tank that sits behind the driver's side door in the later 70's Broncos, but I was told my guys at Tom's Bronco that you want to avoid this, as the parts are super hard to find, and also it was a poor design. No matter what the 4 hoses and fittings into that tank always would break/crack, and leak gas fumes into your cab. It also wasn't the easiest to access. Ford later moved these overflow vapor tanks away from here due to the poor design. The LMR kit is a little confusing with the 4 holes, my understanding is you put a cap (part link below) onto the one nearest the two small holes, then large hole vents from the canister to your air cleaner, and the two small holes are for gas tank intake and purge valve connections. I capped the purge valve connection as my Bronco doesn't have a computer on board like the newer Mustangs did back then.

Sadly these canisters above don't come with the caps, they can be found here, super expensive for a little piece of plastic. Only ordered 1 since it looks like you're supposed to vent the other large hole to your air cleaner. Per Paul's note below, these don't seal the canister, but prevent things from getting in. For certain setups you'll need two of these.
https://www.ebay.com/p/1311225085?iid=255029656081
Ford part number D1AZ-9E602-B

If you want original stock OEM canister go the Mercury Cougar Parts catalog here in Oregon, sometimes these have to be baked to restore I'm told:
https://secure.cougarpartscatalog.com/1919mecofomu2.html – they have brackets and original charcoal canisters that match the Bronco from what I can tell, not sure how well these work, but I'm sure they do.

For the charcoal canister to air cleaner (as the air cleaner will suck in the fuel vapors and recycle them into your engine), go here for a vintage mustang charcoal canister to air cleaner hose:
https://www.mustangsetc.com/3-4-air-cleaner-to-charcoal-canister-fuel-vapor-hose/ – or go find any old aluminum hose, even HVAC ones can work I'm told, this is a 3/4 hose at Mustangs etc... the 3/4 hose was a little big, but I put a sleeve in side it and then clamped it onto the air cleaner intake port. I'm connecting one of the large openings on the charcoal canister

It's also wise to install a rollover valve between the gas tanks & the charcoal canister to prevent fuel from getting into the charcoal canister in case of a heavy nose dive situation, like a steep downhill slope, or a rollover accident. I found this one: https://store.delorean.com/101402-rollover-valve.html , as it looked simplest to hook up and matched my fuel line sizes on my stock aux and main tanks, but any check valve or rollover valve could work. I installed this rollover valve above my passenger side frame rail to a clip in the tub of my Bronco, I have a 3" body lift so it causes the vapor line to raise up quite a bit, and then drops back down as I zip tied the vapor lines to the frame as it travels up to the passenger firewall.

Obviously you'll need a lot of fuel hose line and fuel injection clamps to connect your fuel tank vents from your main and auxiliary tanks all the way to the charcoal canister. Original Ford motor diagrams for EVAP are attached here as well just for Stock/OEM reference. This helped me figure out how to create my own system and follow as closely as I thought I should. I also drew a basic diagram of what I did from my tanks.

Here are additional threads on this topic on ClassicBroncos, they are often incomplete and hard to find, thought I'd put this all in one place for folks if the gas smell is ruining your wife or children's lives.

https://classicbroncos.com/forums/threads/charcoal-canister.313882/#post-3415668
https://classicbroncos.com/forums/threads/mustang-efi-charcoal-canister.313673/#post-3412855
https://classicbroncos.com/forums/threads/charcoal-canister-installation.261451/
https://classicbroncos.com/forums/threads/where-should-the-charcoal-canister-be-mounted.218039/
https://classicbroncos.com/forums/threads/gas-tank-pressure-evap-system-and-gas-caps.310185/
https://classicbroncos.com/forums/threads/plastic-bottle-under-panel-behind-drivers-seat.86497/

Hi there. Following your plan exactly. But that kit is no longer available. The canister itself is, but now I’m hunting a bracket. Any ideas? Thanks for the hard work!

 

[billh1289]

Hi there. Following your plan exactly. But that kit is no longer available. The canister itself is, but now I’m hunting a bracket. Any ideas? Thanks for the hard work!

There’s a couple on eBay. Try a u pull if there is one by you. I just bolted mine to the firewall without the bracket though…