fuel and vent lines?
Thread Starter
Intermediate
Joined: May 2018
Posts: 30
Likes: 0
From: Nova Scotia, Canada
fuel and vent lines?
I have removed my gas tank and found 3 lines, one is the fuel to the carberator and one running up each side to some kind of canister, making 3 lines. What are the two going to the canisters? are they necessary?
Burning Brakes
Joined: May 2004
Posts: 996
Likes: 13
From: Dallas TX
Gas tanks typically have a line going to the engine, a return line for unused fuel coming from the engine and a vent line going to a charcoal canister or remote vent if the charcoal canister has been removed.
The charcoal canister normally has 3 lines,a line from the gas tank, a fresh air line and a line going to the intake of your engine to burn off trapped gas fumes.
The charcoal canister normally has 3 lines,a line from the gas tank, a fresh air line and a line going to the intake of your engine to burn off trapped gas fumes.
Race Director
Joined: Mar 2017
Posts: 11,880
Likes: 4,468
From: Virginia
The same canister, or different? The one going up the driver's side should go to the fuel vapor canister.
There should be two going up the passenger side. One feeds the fuel pump (which THEN goes to the carburetor). The other is a return line from that fuel pump. Is that fuel pump the second canister?
(Image borrowed from LS1 Tech: https://ls1tech.com/forums/conversio...-line-not.html )
There should be two going up the passenger side. One feeds the fuel pump (which THEN goes to the carburetor). The other is a return line from that fuel pump. Is that fuel pump the second canister?
(Image borrowed from LS1 Tech: https://ls1tech.com/forums/conversio...-line-not.html )
Melting Slicks
Joined: Sep 2006
Posts: 2,804
Likes: 468
From: Wichita Kansas
What year is your car? A search on this forum for 'canister' will find information on the vapor canister system. If the system is not hooked up or used, then a vented gas tank cap is needed; it the system is in place and working, then a sealed gas tank cap is used. And much can depend on what year the car is.
Thread Starter
Intermediate
Joined: May 2018
Posts: 30
Likes: 0
From: Nova Scotia, Canada
fuel lines
The same canister, or different? The one going up the driver's side should go to the fuel vapor canister.
There should be two going up the passenger side. One feeds the fuel pump (which THEN goes to the carburetor). The other is a return line from that fuel pump. Is that fuel pump the second canister?
(Image borrowed from LS1 Tech: https://ls1tech.com/forums/conversio...-line-not.html )
There should be two going up the passenger side. One feeds the fuel pump (which THEN goes to the carburetor). The other is a return line from that fuel pump. Is that fuel pump the second canister?
(Image borrowed from LS1 Tech: https://ls1tech.com/forums/conversio...-line-not.html )
its a 74,
Race Director
Joined: Mar 2017
Posts: 11,880
Likes: 4,468
From: Virginia
You certainly need the return line.
In a 74, there may be a fuel separator at the tank on the vapor line. While the tank is out, inspect it. 10 years ago I would have said replace it, but new repro parts aren't always the same quality as road tested parts anymore.
Anyway, now that you know what to look for, I'd search for the parts you may need. As others have said, you need a way to vent the tank, either the stock system or a vented gas cap. The vapor canister does a good job of keeping gasoline fumes from escaping into your garage. There are lots of threads on this.
Good luck!
Thread Starter
Intermediate
Joined: May 2018
Posts: 30
Likes: 0
From: Nova Scotia, Canada
fuel lines
also, is the line going to the canister supposed to be full of fuel? when I cut it out, it was. I did assume the two going down the drivers side were supposed to have fuel, but if the canister is for fumes....then whats leaking, the little thing on the drivers side of the tank?
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Race Director
Joined: Mar 2017
Posts: 11,880
Likes: 4,468
From: Virginia
fuel lines
also, is the line going to the canister supposed to be full of fuel? when I cut it out, it was. I did assume the two going down the drivers side were supposed to have fuel, but if the canister is for fumes....then whats leaking, the little thing on the drivers side of the tank?
also, is the line going to the canister supposed to be full of fuel? when I cut it out, it was. I did assume the two going down the drivers side were supposed to have fuel, but if the canister is for fumes....then whats leaking, the little thing on the drivers side of the tank?
I think our posts just crossed in the night. The thing on the side of your tank is a fuel separator. It sounds like it has failed if you have fuel in the vapor line. Also, your canister may be saturated with fuel. There are threads on this board that can help you either rebuild or replace your canister (repros are available, but perhaps not for every year).
I hope that helps. I'd strongly recommend picking up the 1974 Assembly Instruction Manual and Shop Manual, as it will have the diagrams and instructions that show this, and are specific to your car.
Melting Slicks
Joined: Sep 2006
Posts: 2,804
Likes: 468
From: Wichita Kansas
Replacing charcoal and filter in a canister
https://www.corvetteforum.com/forums...canisters.html
Replacing the charcoal and filter in a canister.
Replacing the charcoal and filter in a canister.