Topic: 1972 Fuel Leak
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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I posted this on NCRS and figured I would share with you.
I was out in my 72 on Sunday and filled the tank before stopping for 1.5 hours. When I came out I found gas dripping out behind the LF tire area. I was confused, knowing the gas line from the tank to the fuel pump is on the RH side.
So I took a look underneath and saw the original charcoal tank had gas dripping out pretty good, about a qt or so into a plastic container we placed under it. I forgot about the gas vapor line from the top L H side of the gas tank. There is a check valve there and a hose running down the LH frame rail to the top of the charcoal tank under the LH fender.
The guys on NCRS confirmed what I suspected, I overfilled the tank, the check valve didn't work as it should and flooded the charcoal tank. Joe Lucia also confirmed the filler necks on the 70-74's are deeper to prevent over filling unless you do what I did and filled it up too much.
I let it drip, started up and it stopped, drove 15 miles home without a problem and it was fine.
I've owned this car since 1979 and never had this happen before so the check valve must have just failed the other day.
Just thought I'd pass it along in case anyone else has this issue.
Gary
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Gary, thanks for posted this info, I also read your post on the NCRS Forum. I've owned several C3's over the years and never heard of that particular issue. I'll keep an eye out when filling my '73. Thanks again, John.
John Sigmund
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Overland Park, KS - USA
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Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
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My 73 did something similar but it wasn't due to over filling the
tank. The valve on top had cracked and wasn't allowing the absorbed vapors from being sucked into the manifold and therefore allowed the charcoal to become saturated. Fixed the valve and was OK after that.
|UPDATED|6/28/2016 5:04:48 PM (AZT)|/UPDATED|
1973 L-82 4 spd
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Overland Park, KS - USA
Joined: 7/9/2003
Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
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gtr1999 said:
I believe you are referring to the black plastic valve correct? If I recall I had another used tank with one on it and it was so brittle it fell apart.
Mine was on top of the canister and IIRC, it simply came unsealed where the two halves we joined.
But that was 20 years ago and I've slept since then. ;)
1973 L-82 4 spd
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Overland Park, KS - USA
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Posts: 914
Vette(s): 1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.
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Another good reason for side exhaust. 
1973 L-82 4 spd
Had the same problem with my 74. Ordered new separator and replaced and in the process of replacing separator found both rubber hoses attaching to valve dry rotted and cracked badly, separator was fine but replaced anyway. I epoxied all joints on valve to prevent future possible leaking of valve.
|UPDATED|7/6/2016 12:52:14 PM (AZT)|/UPDATED|
|UPDATED|7/6/2016 12:52:14 PM (AZT)|/UPDATED|
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DanT
I was out over the weekend. Stopped filling up once the level was at the bottom of the fill neck, came up, topped it a little then stopped. No leaks. That is how I'll leave it until I have time to work on it. Since I don't like the Flow master 50's on the car now I'll handle it with the exhaust change out.
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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