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71 F100, 390. Front of engine bay, passenger side, directly behind radiator - small round canister that seems to be some sort of vacuum related deal... what is it exactly and do I need it? Can't be doing any good right now because the hoses that go to it are rotted anyway. Should I fix the hoses and hook it up or just get rid of it?
I believe that little can is a some sort of a gas tank venting device. Maybe a charcoal filter. After 70 they started putting them on and venting the tanks to them.
If you get rid of that charcoal canister, plug the metal tube. It is a gas tank vent. You can then get a filler tube from a non-vented tank and use a vented gas cap. Mine plugged up on the previous owner so when I bought the truck I got a non-vented tank and filler tube from the boneyard and bought a vented cap.
Some trucks had evaporative control, some did not.
The previous owner was having fits trying to figure out why the truck kept acting like it was running out of gas with fuel in the tank
It's meant to have one of them accordion/paper hoses coming off the top and going up to the air cleaner housing. I bet your air cleaner housing has a plastic attachment on it for it that you've never known what it was for. That way the gas fumes get burnt and not just vented into the atmosphere.
Yep. Mine's round but pretty sure it's the same thing. Thanks.
Originally Posted by Ford_Six
It's an emissios canister. I'd leave it, it keeps the gas smell from the venting tank away from the cab.
Originally Posted by qman
It's meant to have one of them accordion/paper hoses coming off the top and going up to the air cleaner housing. I bet your air cleaner housing has a plastic attachment on it for it that you've never known what it was for. That way the gas fumes get burnt and not just vented into the atmosphere.
Well, no paper hose after all these years, that's fer sure! Just an open hole coming up out of the top, and the rubber line going into the other side, which I guess is coming from the fuel tank, is rotted and full of holes also. Sooooo.... if it's for venting gas fumes and it's all open due to worn/missing hoses... is that why I smell like gas every time I drive the darn truck? Cuz it ain't leaking... and I always seem to smell it on me a whole lot more after I've been under the hood with the motor running.