Sorry. Another Charcoal Canister Question

[Joshua Keith]

1985 K10 Dual tanks.

My only question is where can I vent my charcoal canister. I open the hood and get blasted with fuel vapors. Doesn’t seem safe to me.

I want to use the canister, so plugging it and getting a vented gas cap isn’t the route I want to take.

Is there a way for me to vent this back into the carb?

** Sorry for calling it PVC Doh!

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[Markmx6]

If I remember correctly, you would connect the small line (where the green line goes) to a ported vacuum source and then connect the larger hose under it to manifold vacuum, you could T off of the PCV. This allows full vacuum on the canister, but the ported source opens up the valve... You could put caps on the other fittings.

Hopefully someone will confirm or deny this.

 

[C10MixMaster]

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For your application
#4 is a vent to open air , a filter like a fuel filter would help keep dust n crud out of the canister
#5 to the tanks
#6 #7 should be capped (#6 has to be capped or it will vent vapors to the engine compartment)
#8 goes to timed ported vacuum
#9 goes to manifold vacuum (pvc/purge port)

 

[Markmx6]

Thank you. I guess I had 8 and 9 mixed up with 6 and 7. That makes sense as the new carb doesn't have a bowl vent and 7 and 9 are connected on some vehicles on vehicles that do...

 

[Big Chip]

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I’ve been wondering how these hooked up. What happens when you have 2 of them?

 

[Markmx6]

One for each tank? I believe the one in the third picture will hook up as described above and the first picture will connect to the other tank and then the 2 smaller connections will T off of the first canister

 

[Big Chip]

I’m going to need a lot of vacuum line.

 

[Joshua Keith]

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For your application
#4 is a vent to open air , a filter like a fuel filter would help keep dust n crud out of the canister
#5 to the tanks
#6 #7 should be capped (#6 has to be capped or it will vent vapors to the engine compartment)
#8 goes to timed ported vacuum
#9 goes to manifold vacuum (pvc/purge port)

Awesome! Thank you!

 

[C10MixMaster]

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I’ve been wondering how these hooked up. What happens when you have 2 of them?

if you don't already have the service manual for your 79 downloaded here it is.

http://www.mediafire.com/file/b6uf3...Chevrolet_Light_Truck_Service_Manual.pdf/file

Once downloaded go to section 6E-40 . looks like your going to need a bunch of vacuum line. I'm assuming your running a stock carb and wanting to return it to its stock configuration. also looks like you need to fix the nipple on the one canister.

 

[Big Chip]

if you don't already have the service manual for your 79 downloaded here it is.

http://www.mediafire.com/file/b6uf3...Chevrolet_Light_Truck_Service_Manual.pdf/file

Once downloaded go to section 6E-40 . looks like your going to need a bunch of vacuum line. I'm assuming your running a stock carb and wanting to return it to its stock configuration. also looks like you need to fix the nipple on the one canister.

I have it and did that. I don’t have an EGR or air pump so I can’t use all my nipples anyway. I’m going to hook into the PCV, block the rest and hope for the best. It may not work but I’m going to give it a shot.

 

[75gmck25]

My ‘75 has an older, simpler charcoal canister with only two ports. They are still available online. Newer canisters have special purge valves and vacuum controls, but this ‘75 canister is really simple.

- One port connects with a rubber hose to the metal vent line coming from the tanks (the two tank vents are connected to a T under the truck).

- the other port is a purge line that used to connect to a fitting on the original Quadrajet, but I now have a newer carb. I have now T’d that purge line into the PCV hose and it works fine. Also experimented with installing a fitting on the bottom of the air cleaner and letting it pull air in there, but it didn’t work any better or worse than just using the PCV hose.

Bruce

 

[C10MixMaster]

I have it and did that. I don’t have an EGR or air pump so I can’t use all my nipples anyway. I’m going to hook into the PCV, block the rest and hope for the best. It may not work but I’m going to give it a shot.

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1A and 1B get teed together and go to a ported/timed vacuum source
2A and 2B get teed together and go to the manifold vacuum shared with the pcv
3A and 3B go to the tanks

if you are using a carb with the bowl vent
4A goes to manifold vacuum can be teed into 2A 2B
5A goes to the bowl vent

if not using a carb with a bowl vent cap off 4A and 5A

 

[Big Chip]

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1A and 2A get teed together and go to a ported/timed vacuum source
2A and 2B get teed together and go to the manifold vacuum shared with the pcv
3A and 3B go to the tanks

if you are using a carb with the bowl vent
4A goes to manifold vacuum can be teed into 2A 2B
5A goes to the bowl vent

if not using a carb with a bowl vent cap off 4A and 5A

I appreciate you posting this for me!

 

[gotyourgoat]

I have it and did that. I don’t have an EGR or air pump so I can’t use all my nipples anyway. I’m going to hook into the PCV, block the rest and hope for the best. It may not work but I’m going to give it a shot.

What is the point of having all those nipples then?

 

[WFO]

1985 K10 Dual tanks.

My only question is where can I vent my charcoal canister. I open the hood and get blasted with fuel vapors. Doesn’t seem safe to me.

I want to use the canister, so plugging it and getting a vented gas cap isn’t the route I want to take.

Is there a way for me to vent this back into the carb?

** Sorry for calling it PVC Doh!

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My truck is an 86 K20 HD C6P. It has a hose to the left of the tank vent hose, that goes to some kind of cylinder shaped canister above the drivers fender well that looks to be a vent.

That one and the one to the tank are the only ones connected. All the other hose nipples are left open, and I never smell fumes.