Charvoal vapor cannister

[thethee]

Quick question, my '75 Imperial has this vapor cannister as part of the emissions control and I think it's supposed to have some sort of charcoal. This one is empty so now it's kind of just venting to the atmosphere.

The thing is, how am I supposed to open this thing to even think about replacing the charcoal?

 

[57fury440]

Rock Auto sells the little filter that goes in the bottom. The filter keeps the charcoal from falling out. I replaced them on the Barracudas we have. If I can remember I think the bottom part unscrews. I'm not sure where you can get the charcoal for it.

 

[57fury440]

Giving it more thought. I think the granules are small and can just be poured in from the bottom. The filter just fits above the slot.

 

[CBODY67]

In later years, the can is totally sealed and serviceable as a unit. I remember the earlier ones had filters that allegedly had to be changed every so often. Never did hear about the activaged charcoal being changed, though.

Enjoy!
CBODY67

 

[Gerald Morris]

AC Delco makes a wide variety of charcoal canisters for catching gas tank vapors. Measure what you have, note the number of hoses, then shop it. You might even find something meant to be an OEM replacement. I've discovered this stuff recently, having to deal with this 1983 Dodge pickup we got.

 

[73Coupe]

The filter on the bottom is loose fitting and just a fluffy disc, and I don't think it was meant to retain the charcoal. I think there should be a screen inside the canister to hold the contents.

If empty, I'd think you could just refill with some crushed store-bought plain charcoal for BBQ such as Kingsford. Crush it and run through a sieve for uniform particle size. I'm guessing 1/16" to 1/8" size would be optimal....

 

[57fury440]

73coupe is right, mine does have a screen on the bottom. The granules in my cannister are small, about 1/16 of an inch.

 

['66 Fury I]

Charcoal for acquarium filters should work well. I have used it successfully in filters in drycleaning machines. It is easily available in pet shops. Hope this might help. Lindsay

 

[Ross Wooldridge]

There's one for sale on Facebook right now...

The group is called C Body Mopar Parts Exchange - ignore the fact that it says the post has been removed - it's a private group so you may have to join the group to see the post.
The poster's name is Nick Blake. Facebook

 

[thethee]

Thanks everybody.

Follow up question though. If there's just some screen and fluffy filter to retain the charcoal, isn't that just a big ol vacuum leak?

 

[thethee]

There's one for sale on Facebook right now...

The group is called C Body Mopar Parts Exchange - ignore the fact that it says the post has been removed - it's a private group so you may have to join the group to see the post.
The poster's name is Nick Blake. Facebook

Thanks Ross, but I don't do facebook

 

[CBODY67]

The "vac leak" is from a calibrated-size orifice in the valving on top of the can. Not like unhooking a vac hose or similar. But enough air movement, slowly, to siphon out the accumulated vapors from the charcoal granules. And a calibrated vac leak that is small enough to be compensated for by the carb's fuel calibrations, like a pcv valve is modulated and compensated for.

Enjoy!
CBODY67

 

[Gerald Morris]

Thanks everybody.

Follow up question though. If there's just some screen and fluffy filter to retain the charcoal, isn't that just a big ol vacuum leak?

The redoubtable CBODY67 told you right on. These valves sometimes are controlled electrically, others are pure-dee vacuum actuated. You might look for a new one of those too. I suspect for a C body, it will be pure vacuum-mechanical, but I could easuly be WRONG about that.

I had one controlled by the Lean Burn computer on Billy, our 83 RAM Miser, but replaced that "solenoid" (Mopar nomenclature then) w a purely mechanical solution.

The Amazon keywords are "vapor canister" and "purge valve." Dorman makes plenty of this stuff.

 

[CBODY67]

Separate purge valves were usually modulated by thermovacuum switches. Can't have the can purge with the engine still cold. Otherwise, a vacuum bias system, usually, with the valve as a part of the can assy.

 

[thethee]

This unit is purely vacuum controlled. But thinking about it, I should be able to take it apart as it has to have been an assembly at some point to fit the metal screen. I'll look into it this weekend and let you know my findings.

 

[Sixpactogo]

If I were you, I would try to fill it and re-use it, but if you are interested in replacing it, I have one for sale on FEBO. It was removed from a 73 Challenger many years ago. Same as the one you have. Here are some pics.
$75.00 plus shipping. Shipping is the killer.

 

[thethee]

Happened to stumble onto this page which has some nice detailed pictures of the inside. Thought I'd pass it along.

My Jeep CJ5 Page - Charcoal Canister Rebuild

jeep.smallcraft.net

 

[thethee]

I rebuilt another "non-servicable" part

Wanted to go through the thing thoroughly so I decided to open it up. The bottom does NOT unscrew, it is glued in from the factory, BUT with some persuasion I was able to remove the cap from the bottom. Didnt want to cut the thing in half so with the tiniest flatblade I sort of chiseled away which tool some time but worked fine. Cleaned everything as best I could and reassembled. Got some active charcoal from the store and they also had some aquarium filter elements that fit ridiculously well. Included those to prevent any small bits of carbon getting to the carb later on.

Pics are pretty self explanatory:

 

[thethee]

The "vac leak" is from a calibrated-size orifice in the valving on top of the can. Not like unhooking a vac hose or similar. But enough air movement, slowly, to siphon out the accumulated vapors from the charcoal granules. And a calibrated vac leak that is small enough to be compensated for by the carb's fuel calibrations, like a pcv valve is modulated and compensated for.

Enjoy!
CBODY67

While checking the orifices for blockages I found that it's a pretty large opening and it felt like it WILL be like unhooking a vac hose. Perhaps modulation is done at the carb. HOWEVER, I'm just gonna put it back as is.

 

[MoparapoM]

I 'assume' there's a reason you want the canister to function? I began buying new MoPars in 1970, along with several friends and the first thing that happened when we got home from the dealer was the removal and disposal of that canister. Along with capping off the suction port that pulled from it and routing the Fuel Tank vent correctly.