Non EEC fuel tank vent

ASPEC · Wednesday at 3:45 PM

Hello,
Does anyone have a pic or diagram of the fuel tank vent hose/breather for a 1974 non eec 454?
The PO had capped both tank's fuel sender vents and that is a big no-no. To make matters worse they installed the wrong filler necks (79-84 instead of 73-74) and the caps are not vented either.
I checked the service manuals but didn't find anything. I am assuming it is similar to a differential vent but would like to know how they were run and if there is anything special about the vent type.
Thanks in advance.

75gmck25 · Thursday at 7:26 AM

My ‘75 has three port sending units, and both sides go to a T fitting. That fitting connects to a metal line that runs up to the engine compartment.
At the engine compartment it connects to the vapor canister, and that originally vented into a dedicated port on the carburetor.

In the engine compartment I now have just a vent line from the canister to an open fitting I put on the base of the air cleaner, since my newer Quadrajet does not have the right ports for the canister vent. It probably doesn’t pull much vacuum, but seems to be enough to clear the canister of any vapor.

ASPEC · Thursday at 5:59 PM

75gmck25 said:
My ‘75 has three port sending units, and both sides go to a T fitting. That fitting connects to a metal line that runs up to the engine compartment.
At the engine compartment it connects to the vapor canister, and that originally vented into a dedicated port on the carburetor.

In the engine compartment I now have just a vent line from the canister to an open fitting I put on the base of the air cleaner, since my newer Quadrajet does not have the right ports for the canister vent. It probably doesn’t pull much vacuum, but seems to be enough to clear the canister of any vapor.

I appreciate the response but this '74 2500 came from the factory with NO emissions systems. No evap, No cats, No air pump, etc...
So it won't be the same as any model with an evap cannister.

Non EEC fuel tank vent

ASPEC

Junior Member

75gmck25

Full Access Member

ASPEC

Junior Member

Similar threads

Latest posts

Forum statistics