Anyone else have fuel pour out the vent tube!!???

[chtampa]

How could fuel be pushed up through the vent tube because the vent tube sits right at the top of the tank?
Exactly what we are trying to work out. Why do the vents not cope? No one is dreaming it - it happens and it seems it happen to quite a few people.

Reproduction tanks have a design defect. The vent lines are reversed and the underbody vent tubes get hooked up wrong.

 

[Cojohnso1]

Reproduction tanks have a design defect. The vent lines are reversed and the underbody vent tubes get hooked up wrong.

Interesting. Something to look at. I only know the last 20 years of the car. The guy who had for first 30 years past a few years back. The trail then goes cold. I assumed it's the original or an early OEM. But maybe not?

 

[steve340]

I read that about the tanks vents long/short tube being swapped.
Great !!! Easy fix, so I went under the car and swapped them to the other side. May have been a little better but it still came out the same tube. I extended the short tube with a rubber hose. Then it started to come out the chassis vent line not the short one. That has me baffled.
If my tank was fairly full I could drive 5 miles on a hot day and it would come out.
Then other days I did not notice it at all.
Never a lot maybe 1/4 of a cup at most but enough that when I parked it in the garage there was a reasonably strong smell of fuel. Most of the time I think it came out when I stopped moving.
Sometimes driving the car I would get a faint smell of fuel for a couple of minutes. I figured it could only be venting a bit of gas into the chassis rail and you got the smell of gas until it evaporated.

 

[Billccm]

Capillary effect?
The fact that removing the fuel cap breaks the leak makes me lean towards the capillary effect.

 

[bm02tj]

The gas from the station is in an under ground tank at 50F you take and pump into your car
Then go home a short distance and let it warm up
It expands
Moral of the story is fill when you are going some where or don't fill right full then park

 

[chtampa]

So much of this repop stuff in barely usable. The supplier swears that it will work on your car and you put it on. Expect nothing to work right and check every single part you install. Distributors have known for a while about the tanks being wrong, but they sold them anyway. I have had wrong caps sent to me also. Defective sending units that give you the wrong level of fuel. The list is long and then you make the mistake of thinking that the car is the problem and not the half assed parts you trusted too much. Rant over!

 

[Fran Blacker]

If removing gas cap reliefs tank pressure or stops the leaking. I'd be trying a vented gas cap.

 

[Cojohnso1]

If removing gas cap reliefs tank pressure or stops the leaking. I'd be trying a vented gas cap.

That is what I'm going to try. But again, it can be tough to test. It doesn't happen with every situation. But going to see if it happens at all.

 

[koosh]

Reproduction tanks have a design defect. The vent lines are reversed and the underbody vent tubes get hooked up wrong.

Is there any way of telling if they are reversed while tank is in the car with gas in it?

 

[koosh]

That is what I'm going to try. But again, it can be tough to test. It doesn't happen with every situation. But going to see if it happens at all.

I've read if you put a vented cap on, gas will leak out the cap?

 

[koosh]

I read that about the tanks vents long/short tube being swapped.
Great !!! Easy fix, so I went under the car and swapped them to the other side. May have been a little better but it still came out the same tube. I extended the short tube with a rubber hose. Then it started to come out the chassis vent line not the short one. That has me baffled.
If my tank was fairly full I could drive 5 miles on a hot day and it would come out.
Then other days I did not notice it at all.
Never a lot maybe 1/4 of a cup at most but enough that when I parked it in the garage there was a reasonably strong smell of fuel. Most of the time I think it came out when I stopped moving.
Sometimes driving the car I would get a faint smell of fuel for a couple of minutes. I figured it could only be venting a bit of gas into the chassis rail and you got the smell of gas until it evaporated.

This sounds exactly what's going on with my car

 

[Grabbergreendream]

Guys I may be out to lunch here, but given the circumstances that this occurs(especially the poster that says the leak stops when he removes his cap) its obvious that the vent lines(both!) are under fuel. That leads me to believe that internally, the aftermarket has the ends on the vent lines either angles down into fuel or the tank is slightly shaped incorrectly toforce the ends into the fuel(all of wich expands after fueling up & topping off). I even had problems in my 10' Silverado from squeezing the trigger a few extra "pops" for the first 80k miles, ruining the bypass valve...
Bottom line, stop topping off.
There really is no reason to...
Back to my point, if one vent is leaking, the other is either clogged or dunked in fuel as well. Its physics... Its just leaking from the vent with the least resistance. Fuel wont expand & leak from 1 vent line if the other is free & clear from the fuel in the tank, no matter how high the lines are...

 

[Wietse]

Vents cannot be placed below the fuel level.
It is not only there to let vapour out, it is also there to let air in as fuel is being burned.
To let air in you can't have it below the fluid level, could end up having a crushed coke can below your car.

 

[inverse1216]

this thread has me intrigued, has anyone actually taken a look inside of an original tank and compared it to a reproduction tank? curious to see if the vent tube design is different on the inside between the two. since I am replacing my tank and have the original one as well im going to see if there is any difference between the 2. my new tank is supposed to be here Monday.

 

[steve340]

I have a theory now that the repro tanks may be the cause of 90% of the issues.
I did not have the original tank in my car and the replacement tank I made sure it was clean inside and stuck it in.
I saw another thread were someone had posted pics of the inside of a repop tank.
I noticed the long tube appeared to be soldered to the roof of the tank in several places. This left the tube with several low spots along its length.
I think these could be some of the problem as they make little "traps" like a toilet P trap and render this vent useless until it can push out all the trapped fuel.
I will be very interested to see what you find when you compare the tanks.

 

[dadsbee]

Did you take a flashlight and look inside the tank to see which vent is short and which goes all the way to the rear of the tank???? My Bee is one way and the Bird is the other. Front (short) vent tube goes up into the trunk and back down, rear (long) vent tube goes to the shorty tube up into the shock mount.

 

[koosh]

this thread has me intrigued, has anyone actually taken a look inside of an original tank and compared it to a reproduction tank? curious to see if the vent tube design is different on the inside between the two. since I am replacing my tank and have the original one as well im going to see if there is any difference between the 2. my new tank is supposed to be here Monday.

Am also very interested on what you find for differences!

 

[inverse1216]

well new tank arrived the results are anti climactic. the new tank and the original tank have the same design and placement. the short "candy cane" ext. vent is on the left when looking at the exterior of the tank from the front of the tank and is connected to the long tube on the inside that runs the top side of the tank to the fill. the long vent tube that runs into the trunk is on the right and is the short tube on the inside of the tank. the pictures aren't the greatest but hope they help. I purchased this stainless tank from classic industries if anyone is curious.

 

[steve340]

Thanks for taking the time to post those pictures inverse1216.
It seems the manufacturer of your tank had made the tank like it should be.
Is the car close to going? it would be interesting to find out if your vents work correctly.

 

[Cojohnso1]

well new tank arrived the results are anti climactic. the new tank and the original tank have the same design and placement. the short "candy cane" ext. vent is on the left when looking at the exterior of the tank from the front of the tank and is connected to the long tube on the inside that runs the top side of the tank to the fill. the long vent tube that runs into the trunk is on the right and is the short tube on the inside of the tank. the pictures aren't the greatest but hope they help. I purchased this stainless tank from classic industries if anyone is curious.

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What vendor? And what sending unit are you planning? Very interested in final results. Thank you for your post