How important are the vacuum canisters?

[qu1cks1lver56]

My truck has a couple vacuum canisters under the hood, one near the steering box and one on the firewall. Looking at a sticker under there the one next to the steering box has a line that goes to the fuel tanks (?) and the other one isn't hooked to anything. Everything seems to be fine on my truck with neither of these hooked up I was just wondering if I should have one or both hooked up.

[spinem]

the only thing that can does is act as a filter so no vents draw up dust. No can=dust

[Cherub]

if your emmision exempt they do nothing

[qu1cks1lver56]

No emissions in florida. Which can are you talking about for the dust?

[leegrady]

Charcoal canisters store hydrocarbons, and then allow them to be burned in the engine when certain parameters are met. Hydrocarbon is the scientific description of gasoline vapors. It's what you see sometimes pumping gas, looks kind of like heat waves.

Anyway, your truck will not suffer from any driveability or performance problem associated with the canisters(s) being disconnected.

The one on the firewall. Are you sure that is not a vacuum storage tank? Like for the a/c, and heater vent doors? Such vacuum storage tanks hold a little vacuum so the doors can close after engine shut down.

Interesting comment about the dust. If the one to the tank is connected to the canister dust wont make its way through the line to the tank. The other connections go to the float bowl. Those draw in the vapors. The small fittings on the top go to a thermal switch screwed into the intake manifold, and then to manifold vacuum. When the engine reaches normal operating temp. the thermal switch opens. Vacuum is then directed to the top of the canister to open the valve, and the vapors are then sucked out by the pcv connection to be burned.

[1LowToy]

You would be helping us all out by connecting the canisters properly according to the environmentalists. Gasoline does give off toxic vapors. I've never noticed any lack of performance due to using them. The fuel system is sealed off from the atmosphere and the charcoal canisters absorb the fumes until the engine is ready to purge them of the vapors. By having your fuel system is sealed off from the atmosphere you have sealed out the dust. On the bottom of most canisters there is a filter that needs to be changed periodically. I have seen some Ford trucks that the canister was located below the bed of the truck. The filters became plugged with dust, then deteriorated away. The result being the dust inturn went through the canister and into the engine intake and made dust of the piston rings. The company had a fleet of smoking Fords with only 50K miles at auction.

[spinem]

as the pump removes fuel and feeds the motor the tank emptys. that space has to be filled by something. the "to tank" rubber hose, vents the tank. so you tell me, if its sucking whats stopping debris from entering the line and plugging it? thus causing a condition a member (cannot remember who) suffered from.

all the connections from the carb-can catch vapor yes, agreed. How ever disconnecting them will do nothing. I disconnected them on my 71 gmc and 72 chevelle. The chevelle ran better with them disconnected..... gmc.. no difference.

If you wanna save birds, be legal and safe, keep the can. Want a "clean"look, chuck it.

[qu1cks1lver56]

Thanks for the info guys.