Fuel vent tube

[RYO5566]

Hello!
I'm about to weld a trunk extension to my car, and I'm thinking of sealing the hole in the fuel gas vent tube with welding.
Before the restoration, the vent tube was installed, but the hose was not connected to anything.
It is supposed to be connected to a hose rather than a branch of the fuel tube, but I want to seal it with a rubber valve or something and also seal the hole where the trunk extension is attached to keep it simple.


Is a fuel vent tube necessary in this state?
Will there be any problems if I don't attach it?
Is there anything I can use to replace the vent tube?
I wasn't sure whether to post on the restoration forum or the fuel forum.


Thank you for reading until the end!

 

[Mopars & Missiles]

Your tank NEEDS a vent to atmosphere. If you don't connect this nipple to the tube going under the car to the frame rail, you will have terrible gas fumes inside the car. You won't enjoy driving the car with those fumes.

Alternative might be to eliminate that nipple and find a gas cap that is vented.

 

[Steve340]

You do need a vent on a fuel tank.
The 1971 vent system you have in the picture works very well but takes some work to connect up.
Also you need the gas tank with 4 nipples on it.

 

[RYO5566]

Thanks for the advice!
The original fuel tank had two nipples instead of four.
So there was nothing connected to the vent tube from the beginning.
I have one more question: what is the fuel ECS system?

You do need a vent on a fuel tank.
The 1971 vent system you have in the picture works very well but takes some work to connect up.
Also you need the gas tank with 4 nipples on it.

 

[Steve340]

You need to look at the factory service manual to correctly identify what is what. It will also explain how the vent system actually operates. You have posted pictures of bits from two different systems.
Look at the 1970 and the 1971 FSM book.
In the picture you have posted in #4 neither is the vent.
The yellow one is the feed to the fuel pump and the blue one is the return line from the fuel vapor separator which is in the liquid fuel feed line.
I looked at my 1970 FSM and the and you could get two factory systems the Clean Air System CAS or the Evaporation Control System ECS.
I didn't know this before but the ECS is renamed in 1971 and becomes the Vapor Saver System but it is exactly the same configuration.
The ECS is very well designed and works good. You need the correct vacuum/pressure cap and the vapor liquid separator which is pictured in your first post. If connected correctly and with all it's tubes etc as the factory intended the VSS is by far the best.

 

[RYO5566]

Your tank NEEDS a vent to atmosphere. If you don't connect this nipple to the tube going under the car to the frame rail, you will have terrible gas fumes inside the car. You won't enjoy driving the car with those fumes.

Alternative might be to eliminate that nipple and find a gas cap that is vented.

Hello!
Thanks for the advice!
The vent tube in this photo was not originally connected, and the fuel tank also had two tubes.
I looked at photos of the fuel tube area of various Challengers, and it seems that the vent tube is indeed used to release evaporative gases.
As advised, the fuel cap has been replaced with an aftermarket part that has a lock, and there seems to be a gap that allows gas to escape.
Also, if I were to install a vent tube in its current state, I think the piping would be like this, as in the photo in this forum, but does the pipe go inside the frame?
Also, there are some with one vent tube and some with two; is there any difference?

 

[MoparCarGuy]

Several of your pictures are of a Cuda trunk interior instead of a Challenger. Different configurations.

 

[RYO5566]

Several of your pictures are of a Cuda trunk interior instead of a Challenger. Different configurations.

Hello！thanks for the advice!

 

[RYO5566]

You need to look at the factory service manual to correctly identify what is what. It will also explain how the vent system actually operates. You have posted pictures of bits from two different systems.
Look at the 1970 and the 1971 FSM book.
In the picture you have posted in #4 neither is the vent.
The yellow one is the feed to the fuel pump and the blue one is the return line from the fuel vapor separator which is in the liquid fuel feed line.
I looked at my 1970 FSM and the and you could get two factory systems the Clean Air System CAS or the Evaporation Control System ECS.
I didn't know this before but the ECS is renamed in 1971 and becomes the Vapor Saver System but it is exactly the same configuration.
The ECS is very well designed and works good. You need the correct vacuum/pressure cap and the vapor liquid separator which is pictured in your first post. If connected correctly and with all it's tubes etc as the factory intended the VSS is by far the be

You need to look at the factory service manual to correctly identify what is what. It will also explain how the vent system actually operates. You have posted pictures of bits from two different systems.
Look at the 1970 and the 1971 FSM book.
In the picture you have posted in #4 neither is the vent.
The yellow one is the feed to the fuel pump and the blue one is the return line from the fuel vapor separator which is in the liquid fuel feed line.
I looked at my 1970 FSM and the and you could get two factory systems the Clean Air System CAS or the Evaporation Control System ECS.
I didn't know this before but the ECS is renamed in 1971 and becomes the Vapor Saver System but it is exactly the same configuration.
The ECS is very well designed and works good. You need the correct vacuum/pressure cap and the vapor liquid separator which is pictured in your first post. If connected correctly and with all it's tubes etc as the factory intended the VSS is by far the best.

Thank you for looking into it!
If I want to use ECS, I have to replace the tank itself with a special one.
I think I'll just have to use the nipple from the fuel filler port and run a pipe through the frame to let the steam escape.
Thank you for your kind advice!