Drivers side louver vacuum tank
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 8,887
Likes: 4,071
From: US-PNW
Yep, contains charcoal to absorb fuel vapors. You should have a steel fuel line running along the frame rail above the brake line. It is also connected to the canister with a rubber hose. The engine vacuum pulls any vapors from the canister into the engine to burn it off. It was an early way of capturing fuel VOCs and is necessary if you have the non-vented gas cap; it doesn't use any engine power to operate and is a good idea to keep functional.
Instructor
Joined: Dec 2011
Posts: 189
Likes: 54
From: Virginia
Here's a procedure on how to 'rebuild' the canister with new charcoal:
1974 Charcoal Canister Rebuild
NOTE: The `74 should be similar to your `72
1974 Charcoal Canister Rebuild
NOTE: The `74 should be similar to your `72
Instructor
Joined: Dec 2011
Posts: 189
Likes: 54
From: Virginia
Here is another procedure that refills the charcoal from the bottom of the canister and shows how to check the purge diaphragm:
Rebuild Fuel Vapor Canister
Rebuild Fuel Vapor Canister
