Fuel tank vent
We need to start with "what is the year make and model."
Why?
Because up into 69, ALL A bodies had a simple vent to the atmosphere in the filler tube
In 70--71 ish SOME cars had CA mandated evap emission controls and 71-is--72 and later Federally. Additionally, THAT SYSTEM (the evap control system) CHANGED some almost every year to 76.
The first couple years had a big can in the trunk, the vapor separator. There were tubes/ hoses coming into the trunk from the tank, and ONE vent line going clear up into the engine bay. THAT IS your vent AND MUST be open or else other provisions
So if you have a "non evap" car, you have an open tank vent, and can create a return line to the tank
If you have an evap controlled car, either add a second return line, and keep the evap vent line clear for a vent, or else create the 69/ earlier style vent --which is documented in service manuals.
You can download many service manuals........free........from MyMopar
Early style evap system with separate vapor separator. LATER THIS WAS incorporated right into the tank---with only the one 1/2 line going to front for the evap plus the feed line of course
This is the "69 and earlier" atmospheric vent, and any of the overlap years of about 70-71 without evap
We need to start with "what is the year make and model."
Why?
Because up into 69, ALL A bodies had a simple vent to the atmosphere in the filler tube
In 70--71 ish SOME cars had CA mandated evap emission controls and 71-is--72 and later Federally. Additionally, THAT SYSTEM (the evap control system) CHANGED some almost every year to 76.
The first couple years had a big can in the trunk, the vapor separator. There were tubes/ hoses coming into the trunk from the tank, and ONE vent line going clear up into the engine bay. THAT IS your vent AND MUST be open or else other provisions
So if you have a "non evap" car, you have an open tank vent, and can create a return line to the tank
If you have an evap controlled car, either add a second return line, and keep the evap vent line clear for a vent, or else create the 69/ earlier style vent --which is documented in service manuals.
You can download many service manuals........free........from MyMopar
Early style evap system with separate vapor separator. LATER THIS WAS incorporated right into the tank---with only the one 1/2 line going to front for the evap plus the feed line of course
This is the "69 and earlier" atmospheric vent, and any of the overlap years of about 70-71 without evap