The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Charcoal canister- how does it work

gclark · 01-25-2016, 11:02 PM

I have a 72 with 350 cid Quadrajet. It has the original evap canister mounted next to the battery.

The canister has a valve on top with 3 hose connections. It also has a filter on the bottom.

The three hose connections are:
Canister to fuel tank
Canister to PCV and carburetor manifold vacuum
Canister to carburetor ported vacuum

Questions: what is the function of the valve on top of the canister? Why is the ported vacuum line necessary?

Thanks in advance.

01-25-2016, 11:02 PM	#1
gclark Registered User Join Date: Aug 2006 Location: Bama Posts: 12	Charcoal canister- how does it work I have a 72 with 350 cid Quadrajet. It has the original evap canister mounted next to the battery. The canister has a valve on top with 3 hose connections. It also has a filter on the bottom. The three hose connections are: Canister to fuel tank Canister to PCV and carburetor manifold vacuum Canister to carburetor ported vacuum Questions: what is the function of the valve on top of the canister? Why is the ported vacuum line necessary? Thanks in advance.