Gas leak help
Thread Starter
Instructor
Joined: Jul 2010
Posts: 102
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Gas leak help
When I fill up my 76 Vette gas leaks out under the tank area. As you look at the car from the rear it drips on the right side from somewhere under the tank area and it is getting on the muffler. After the car has been driven several miles the drip stops. Maybe when its 3/4 full the leaking stops. Anyway has anyone else had this problem and what do you think it might be causing the leaking. Can it catch on fire leaking on the muffler? I really cant tell where its comming from. Thanks
Melting Slicks
Joined: Mar 2009
Posts: 3,126
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This is a pic. of my '77 tank. There are several possibilities as to the source of the leak. The seal around the sending unit, the hose that leads to the fuel pump, however it should leak at all times. Are the hoses original to the car? The tank could have a small pinhole in it. There is a fuel overflow hose that attaches to the rubber surround around the filler cap. The latter would only drip if you spill fuel while refueling. The gas can indeed ignite if the temperature of the muffler reaches the flash point for gasoline. Get under the car and find the leak before you drive it. Second pic. shows overfill drain hose. Be safe. mike...
Thread Starter
Instructor
Joined: Jul 2010
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mds3013 thanks for the pics and reply. Yes I think the hoses are all origional and its not comming out of the overflow hose. It just started doing this last week. I thought I had just overfilled it because the leaking stopped after driving it some. It was half full so i filled it up again today but stopped when it clicked off and I didn't squeese anymore gas in like I did last time but after getting home I noticed it leaking again.
Team Owner
Joined: Aug 2000
Posts: 21,453
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From: Massillon,Ohio USA
2020 C3 of the Year Finalist - Unmodified
Cruise-In VI Veteran
St. Jude Donor '08-'09-'10-'11-'12
...I had a similar problem on my old '75 about ten yrs ago. It wouldn't leak enough fuel to puddle on the ground, but enough to drip on the passenger side muffler and stain it. You could also smell it. It ended up being the larger rubber fuel supply line(there are two, one smaller return line & larger supply line). Had a small "starburst" or pinhole in it. Both of these rubber lines if original should be replaced. Probably well past there time.
Le Mans Master
Joined: Sep 2004
Posts: 5,116
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From: Livonia MI
As with any fluid leak problem, easiest way is putting some UV trace dye into the fluid, and driving the car around normally for awhile. Give things a few days, then scan the suspect area with a UV trace light in low light conditions, and it will show up. These kits aren't very expensive, and have dyes for any fluid. Engine oil, radiator, power steering, tranny, rear axle, AC, ext. You can even have dyes for each application, glowing in different colors. Really nice set up to have, for older cars.
