Vapor Recovery / Charcoal canister line to air Cleaner

[DirtDonk]

Yes, that’s what it’s for on aftermarket filters. They sell inexpensive plastic elbows that screw on right there.

 

[SeaVee]

So, at the same point in my 77 resto. I have the vapor line run from the rear tank to the rollover valve to the original canister. But how about the aux tank? How do you run the vapor line from there to the canister? My body guy removed the aux tank and didn’t document how it was run. Could I just use a vented cap on the aux tank? TIA

 

[Slowleak]

So, at the same point in my 77 resto. I have the vapor line run from the rear tank to the rollover valve to the original canister. But how about the aux tank? How do you run the vapor line from there to the canister? My body guy removed the aux tank and didn’t document how it was run. Could I just use a vented cap on the aux tank? TIA

Here is a ‘77 diagram…

 

[Meddle]

Here is a ‘77 diagram…

Excellent, that’s very helpful to visualize it. Looks like the vapor line simply Ys to aux and main tanks before the rollover valve which makes sense.

 

[DirtDonk]

Matches what I've seen also. Does your steel line still have the junction point? Maybe capped off?

As far as running a vented cap, yes you can. But it not only defeats the purpose/function of the canister and would likely let fumes be your friend (or worst enemy!), but also means you need to make your own cap vent.
The standard vented cap will not fit into the filler neck, so you'd end up drilling a hole in a regular cap.
Might be a compatible cap somewhere, from some other vehicle, but I don't think I've ever seen it mentioned, if anyone ever found one.

The good news is, that with the '77 gas doors and pockets with drains, if fuel sloshes out the hole, it won't go down the side of your Bronco's fender!
Seems best, and probably easiest, to "Y" it or "T" it and let it all work together.
Hopefully yours still has the junction. And you have all the pre-bent tubing still?

Paul

 

[SeaVee]

Man- thanks so much! I was wondering what that T was for before the rollover valve but didn’t put 2+2 together because I never saw the aux tank setup before my body guy removed it. I bet I threw the T piece away, is that something easily sourced?

 

[DirtDonk]

No idea at all. Never tried to find one. Could be a standard T, and maybe you have to make your own. But I don’t remember ever talking about it here before.

 

[904Bronco]

Man- thanks so much! I was wondering what that T was for before the rollover valve but didn’t put 2+2 together because I never saw the aux tank setup before my body guy removed it. I bet I threw the T piece away, is that something easily sourced?

Dorman's Help Line has Brass tee's, usually a set of three various sizes 1/4, 5/16, 3/8"

 

[Meddle]

I disconnected and pulled out the condensing tank from my cab today. Removing the metal protective panel was like busting into a time capsule, with original paint visible on the quarter panel and even the original sticker perfectly intact on the tank itself, reading March 19 1974. 50 years ago!

I see there are two vent lines going to/from my main tank (interestingly, only one from the aux tank). I assume one is the vent line and the other is a condensate return line. Since I only need one line from each tank to plumb into my charcoal canister, can I simply cap one of the lines?

 

[DirtDonk]

Yes. You are correct that the additional line is for returning to the main tank only.
No longer needed if using the newer style of canister, or when deleting the system entirely.

 

[Meddle]

I just completed my conversion to charcoal canister and wow what a difference it made. No more fuel smell. Absolutely eliminated. Highly recommend it for anyone on the fence.

 

[DirtDonk]

Great report! Thanks for the follow up.

 

[Soylent]

What canister is that?

 

[SeaVee]

Looks original

 

[SeaVee]

Could you shoot a pic of where the hose enters your air cleaner? TIA

 

[Meddle]

What canister is that?

Dorman 911-198 Vapor Canister​

 

[Meddle]

Could you shoot a pic of where the hose enters your air cleaner?

On the cleaner there are two punch out spots for an elbow which bolts to the bottom of the cleaner body. I used Edelbrock 1205 PCV.

 

[SeaVee]

Many thanks!