vapor canister

[John H.]

72 vapor canister 350. What is inside canister? Can new replacement contents
be purchased from some vendor? I am original owner of 72, canister has never
been disturbed, however I am thinking of opening it up etc.
I get a noticeable gas smell AFTER car has been driven and then parked.
The carb was rebuilt about 2 years ago. Smell started about a year ago.
I cannot locate any leaks on intake. ANY SUGGESTIONS?

[Joe L.]

Re: vapor canister

John-----

The canister contains activated carbon in some form as well as other support structure. I've never dissected one of these things. As far as I know, no one sells just the contents of these things---they are usually unit-replaced. If one wished to preserve the outer shell for originality purposes, it might be possible to transfer the contents of a new canister to an old one. A new canister is still available from GM under GM #17063011 for about 75 bucks, GM list.

I doubt that your gasoline odor problem is due to the canister, although it's not out of the realm of possibility. If you have a base engine 1972 with Q-Jet, the more likely cause is fuel dripping into the mainfold after shutdown. This may be due to leaking soft plugs in the base of the fuel bowl assembly. Q-Jets are notorious for this problem.

[Mike M.]

Re: vapor canister

had occassion to remove two cannisters from a pair of early 80's S-10's the other day. one smelled like varnish and a lot heavier than the other which didn't smell of old gas. smelly one off a 200K mile truck, other off a 50K truck. i suspect they eventually become fully saturated and would need replaced.the two of them look identical to the original one on our 74 20K vette. why not visit the local junk yards instead of a 75 buck trip to Mr Goodwrench? mike

[Duke W.]

Re: vapor canister

Theoretically the activated charcoal should never "wear out". A few years ago I detected a strong fuel smell from my Cosworth Vega, and it turned out there was a crack in the short rubber hose that connects the rear evap pipe from the tank to the front evap pipe that routes to the cannister. This short hose is located on the cowl behind the engine.

There are a lot of pipes and hoses that make up the evaporative emission control system, and the hoses in the engine compartment degrade with heat, so check all the hoses and connnections including back at the tank before you condemn the cannister. There is a line from the tank and one from the carb bowl, plus the purge line and purge valve signal line from the carb.

Also wash or replace the air filter at the bottom of the cannister and check the purge valve for proper operation. The basic service information and system schematic is in your CSM and virtually all CSMs of the era as all GM cars used the same basic evap system.

I bought a new Purolator evap cannister filter at Pep Boys for about a buck and a half, and it looks exactly like the original. Tens of millions of GM cars used the same cannister and filter.

Duke

[John H.]

Re: vapor canister

Duke and the rest of the gang, thanks for your comments.
I'll try a few of the suggestions. Big John