Charcoal canister purge valve question

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

Checked with the manufacturer of the canister to make sure the purge port isn't a purge valve. It isn't so DJ using the external purge valve is the way to go.
Checked the canister purge port on the quadrajet today and it is ported vacuum. Excellent!
Thanks

I can't picture how to connect an external purge valve to a canister. Image of the assembly would be great.

[howzzzit]

Rust, the main line will be teed to the pcv and the ported line is just to signal the purge valve to open and dump into the pcv line.

[71CHEVYSHORTBED402]

The line from the PCV to the carb. has a tee anyway, to reduce it from 3/8" to 1/4", which connects to PCV on the canister.

By the looks of the 214-2294 Vapor Canister Purge Valve, would it be correct to install it near the replacement canister? It looks like you just cut the PCV hose near the canister, install the valve to the PCV hose, install the vacuum hose and done.

In other terms, this seems to demonstrate how the original cans work, and how to modify the evap. system using the newer cans. At least to my understanding. Any corrections appreciated.

[howzzzit]

Tony, the top fitting is marked purge and the bottom is tank vent. No vent marked pcv on the one I ordered. (not here yet) Hooking up the main line on the valve to this purge fitting. I measure 5/16 on the purge valve line so I ordered a 3/8 x 5/16 red tee for the pcv tie in. My carb has a canister purge vent which is ported vacuum and will open the purge valve when off idle. I think this Frankenstein deal will work. Where did you find the diagram? I had to draw one in my head.

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

Tony, the top fitting is marked purge and the bottom is tank vent. No vent marked pcv on the one I ordered. (not here yet) Hooking up the main line on the valve to this purge fitting. I measure 5/16 on the purge valve line so I ordered a 3/8 x 5/16 red tee for the pcv tie in. My carb has a canister purge vent which is ported vacuum and will open the purge valve when off idle. I think this Frankenstein deal will work. Where did you find the diagram? I had to draw one in my head.

PCV on the old canister is Purge on the newer ones.

5/16" for the PURGE port or the valve? Hmm... The existing PCV hose is 3/8", and reduced to 1/4", which ran to PCV on the old can (PURGE on the new can). The only 5/16" hose in the original EES system is for TANK. Where do you plan to install the purge valve? Bummer of it has to be installed by the 3/8" hose; i wouldn't think it hangs above the manifold. Hoping it installs with the 1/4" hose, near the can.

I drew up the illustration, so this replacement can business can sink into my head...Already had the info. for the original can.

I revised the illustration (1973-74) because I think the cans changed in 1973. Also, the 911-261 can's stated dimensions are larger than original, perhaps it won't fit in the original bracket and strap. That's assuming the stated product dimensions are right, which they probably aren't, I'll bet that's the package dimensions.....Can #215-153 shows closer dimensions to common 71-72 truck canisters, which are approx. 5.75" tall and 5" wide, or 6.75" tall if counting the valves.

[howzzzit]

Tony I measure 5/16 on the valve through line. Maybe I'll have the can today. Film at 11.

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

Tony I measure 5/16 on the valve through line. Maybe I'll have the can today. Film at 11.

Well, 1/4" is almost close 5/16" Make sure your new hose is for fuel (PCV/EEC), IMO. Some install plain fuel hose, but the PVC/EEC hose is specifically for the task.

Edit.... For what worth I asked for the dimensions on a 17113148 canister. It's 5" wide like our old cans. It's 6" tall without the valves, which about 1/4" taller than our cans. Perhaps a light provision necessary, I don't know why this can for example wouldn't work like original by adding a purge valve.

Perhaps available cans (1973-ish) are the same size for standard fuel tank capacities, which our cab tanks are approx. 21 Ga.

[howzzzit]

Question. Will I need to remove the battery tray to remove the canister??? Looks real tight in there.

[Rich72C10]

I didn't need to pull my battery tray. There was just enough room to get it out with its brace (as one), though for a bit I thought I was going to need to pull it. I did have the 12v power junction off the fender so those power lines were out of the way.

[howzzzit]

Thanks Rich. I was hoping to hear that. Should be interesting. I don't need to remove the bracket unless I need to. Just the canister.

[howzzzit]

Rich, I held my tongue just right and the whole thing came out. The best part is the aftermarket canister fit the bracket. I was a little worried about the fit.
Thanks

[Rich72C10]

Originally Posted by howzzzit

Rich, I held my tongue just right and the whole thing came out. The best part is the aftermarket canister fit the bracket. I was a little worried about the fit.
Thanks

That’s great to hear, would love to see photos with it all connected up and well it works!

[howzzzit]

HEY! You didn't tell me how hard it was to reinstall the bracket. Sheet metal moved just enough so the front screw couldn't start. I got it. By the way the canister is a touch larger diameter than the original. Not enough to be a problem. Snugged right up. I pulled the filter from the bottom of the old canister. I advise anyone to do this over a garbage can. Everything was dissolved inside except the charcoal. Still loose after 50+ years and smelled like gas. There's a lot of charcoal in there and it goes everywhere. Don't ask how I know this.
Thanks

[71CHEVYSHORTBED402]

I can't remember if I pulled my can and bracket as a unit, but I recall it can be done either way. I pull the battery just cuz. If I read you right, the fender ("sheet metal") moved a touch. Perhaps a good reason to pull the can w/o the bracket.

I have a new system short the can is used. It's original and in prime shape cosmetically, and I tested the diaphragm before I installed it. But after 300 miles, my garage stinks when I repark the truck, for about an hour or so. My suspicion is the charcoal has seen enough emissions.

They leak due the foam rubber at the bottom is toast.

So anyway, I'm probably due a new can and IMO, better to buy new if it works than refresh an original can, at least for convenience.

Did you get everything hooked up? We're waiting for a full report

[howzzzit]

My diaphragm tested ok on the old canister. It held a vacuum. DJLambert said the diaphragm would open the pcv port when activated. That would purge the canister. My pcv port was open at all times. By the way my canister was not hooked up, but just the tank vent attached. Got tire of smelling gas in the garage. Been that way for a long time.

[71CHEVYSHORTBED402]

Originally Posted by howzzzit

My diaphragm tested ok on the old canister. It held a vacuum. DJLambert said the diaphragm would open the pcv port when activated. That would purge the canister. My pcv port was open at all times. By the way my canister was not hooked up, but just the tank vent attached. Got tire of smelling gas in the garage. Been that way for a long time.

Kind of sounds like it only tests if it's working right. I'm reminded of the air cleaner diaphragm, only perhaps the opposite. It didn't hold vacuum with a tester, but works like it's supposed to with everything hooked up. I read someplace that's the only way to "test" the air cleaner diaphragm anyway, so long as the cleaner's temp, vac what-ever called sensor, spring thing is working.

[dmjlambert]

So what is the end of the story? Does it do anything about the gas fumes?

[howzzzit]

Does great just sitting there. Haven't fired up yet.

[howzzzit]

It ain't beautiful, but it works

[Rich72C10]

Nice setup, bet you are glad to be done :-)

I know when I got my non-working canister replaced/working with recharged charcoal it eliminated all the gas fumes. It was well worth the effort, IMO.

[71CHEVYSHORTBED402]

That's awesome, thank you and Lambert.