# 65 GTO Fuel Tank-Vented Cap or Not



## Randaaay (May 30, 2013)

I'm new to this site. Have a 65 GTO clone convertible, added a 1965 389-60 over, tri-power, 4 speed, 355 posi. It is a not hooked up factor air car with PS, PB. About the only thing original to the car is the passenger rear quarter! There are two fuel lines running from the gas tank sending unit-I think one is the fuel return line from the fuel filter or the fuel pump, can't remember. The gas tank filler neck has what appears to be a vent tube about 6 inches in length but has nothing connected to it. Fuel will leak from the tube. Questions: (1) Is this "vent tube" supposed to be connected to something? (2) If so, where can I learn how to hook up the vent tube? (3) Should I have a vented or non-vented gas cap? (4) The Goat was in the shop and not running for about 8 months and my rallye dash gas gauge stopped working. I am chasing that whopped puppy too and will probably install a new sending unit since I've changed out the dash gas gauge. The rallye gauge dash harness appears to be properly connected. So many issues, so little time, so little money too!


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## 05GTO (Oct 6, 2004)

Randaaay said:


> I'm new to this site. Have a 65 GTO clone convertible, added a 1965 389-60 over, tri-power, 4 speed, 355 posi. It is a not hooked up factor air car with PS, PB. About the only thing original to the car is the passenger rear quarter! There are two fuel lines running from the gas tank sending unit-I think one is the fuel return line from the fuel filter or the fuel pump, can't remember. The gas tank filler neck has what appears to be a vent tube about 6 inches in length but has nothing connected to it. Fuel will leak from the tube. Questions: (1) Is this "vent tube" supposed to be connected to something? (2) If so, where can I learn how to hook up the vent tube? (3) Should I have a vented or non-vented gas cap? (4) The Goat was in the shop and not running for about 8 months and my rallye dash gas gauge stopped working. I am chasing that whopped puppy too and will probably install a new sending unit since I've changed out the dash gas gauge. The rallye gauge dash harness appears to be properly connected. So many issues, so little time, so little money too!


I believe 65 was the first year for the trunk vent tube, here is a picture of my 67 which should be the same as 65,


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## olde-goat (Feb 1, 2009)

The fuel filler neck on both my 65s have about a 1" long nipple soldered on the right hand side of the tube facing the passenger side. A short length of rubber gas line hose runs from the nipple to a small U shaped tube. The tube is attached to a small hanger spot welded to the underside of the trunk floor just below the trunk latch. The ends of the tube are pointed to the ground, one end remains open and acts as a vent, other end is attached to the rubber hose. I am sorry, but I don't have a picture that I can send you. If I recall there has been past discussions on this topic, do a search and you may find some pictures. I tried to purchase this vent but none were available a few years back only the later vent as posted by 05GTO, this style does not fit the 65. I had to make my own out of short length of steel gas line and rubber gas hose.


Also there is no vapor return line on a NON AC 65, I believe that this was started in 67.


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## Randaaay (May 30, 2013)

After your response a light bulb finally went off. I also have two 65's and looked at the red convts set up which is non-air. The vent on it is as you described. I did a quick look at Ames parts catalog and see they have a 65 gas tank vent kit for $17. Thanks for the assist.


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## Randaaay (May 30, 2013)

The vent on your 67 is different than the 65 per Ames catalog and the later response from olde-goat. The 66 and 67 appear to have the same parts kit though. Thanks for getting me started.


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## David Bradshaw (Apr 14, 2016)

Im also chasing a vent tube question on a 65 non air 4 speed GTO convertible. As there is no hole in the trunk, how do you attach the u-shaped metal tube to the car/vent tube????????????????


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## john23 (Mar 6, 2016)

non vented gas cap, otherwise, because of GM genius, the low angle fill tube, behind the license plate, will allow gas to slosh out the vented cap every time you whack the throttle....


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## 1965 TC4d (9 mo ago)

David Bradshaw said:


> Im also chasing a vent tube question on a 65 non air 4 speed GTO convertible. As there is no hole in the trunk, how do you attach the u-shaped metal tube to the car/vent tube????????????????


Hello,

I realize this is an old thread but did you ever get a response to where/how to mount the vent tube extension on a '65 Tempest?

Thanks


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## GTOJUNIOR (Aug 7, 2011)

'65 vents are below the tail panel ledge. 
The nipple on the tank filler tube uses a short rubber hose and runs upward to another small "U" shaped piece of tubing. 
This hangs/hooks onto the factory hook on the underside of the ledge behind the bumper.


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## 1965 TC4d (9 mo ago)

Spot on response and excellent pics too.

The two '65 tanks I just bought wound not fit due to the large up angle of the filler tube. Neither of those tanks had a vent on the filler tube.

Ordered a '66 tank that has a much flatter filler tube but also has a vent.

Your description and pics solved the vent issue.

I see Ames has this vent available. Will order one and get the tank in.

Thanks


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## 1965 TC4d (9 mo ago)

Do you know if there was a '65 mid year change to a vented tank or are the tanks listed for a '65 just incorrect? Seems like its across the board for '65 tanks.


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## GTOJUNIOR (Aug 7, 2011)

I'm not a '65 "expert" but have 3 '65 GTOs to use for reference at the shop on a regular basis and they all have the vent pipe on the filler neck. 
The red drop-top is were the first photos came from.

Even this page from the parts book reflects this.


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## 1965 TC4d (9 mo ago)

That sir, is very useful.

Thanks


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