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I have a fuel leak at the tank on a hot day with a not-quite-full tank. The gas drips down, very close to the exhaust. I note from diagrams that there is a "separator" with 2 lines, one of which is an overflow, I suppose.
It is difficult to see up in there, unless I drop the tank. Any advice?
Drop the tank and check it out. Those fuel separators are prone to cracking. No way to know or repair it without dropping the tank. Which by the way is very easy to do.
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Originally Posted by paulebrown
What is the purpose of the separator? I can see that there is an overflow, but the other? A return from....where?
The fuel separator allows the gas fumes to escape from the tank but not raw gas.
The fumes travel down the driver's side tubing and into the vapor canister where they are recycled as you drive.
I think you can find a thread on this here. Been trough this with my 73 and strongly advise you just bypass this separator and install a vented cap on the tank. If you go to the trouble of replacing the separator with a replacement from any of the corvette parts places you will find they crack and leak - period - they are all poorly made. Do a search on this forum and see for yourself. Enough said.
Depending on your exhaust system you don't have to actually drop the tank to remove the separator if you can remove the drivers side muffler.
Mine started having a strong gas smell at the drivers rear wheel so I had to remove and re-seal the separator.
PIA to reach up there but easier than dropping the tank
M
I have a fuel leak at the tank on a hot day with a not-quite-full tank.
Don't discount the effects of volume expansion due to temperatures. Consider the scenario of filling your tank (20 gallons) from the underground tanks where the fuel is ~60°F. The temps during the day reach 100°F. That temperature change will expand the gasoline in your tank by about 8/10ths of a gallon. That expansion has to go somewhere, so out the overflow hose it goes – likely located at the rear panel by the passenger muffler. When filling on days in which the temperature is expected to be high, and when you aren't driving any significant distance after fill-up, perhaps don't top it off to full.
Thanks guys,
Not sure about this but it appears to be only one hose attached to the tank (on driver's side). So I guess I need to do some driving to lower the fuel in the tank. And yeah, it looks like I may be able to get up in there if I drop the muffler and exhaust.
Again thanks...as you can guess, I'm not a kid anymore and crawling under ain't no fun, and my mechanical knowledge has gone with the other stuff...
For a '72, you should have three connections to the tank: steel lines running from the tank up the frame rails on each side of the car. The driver's side is the EVAP line (run in parallel with the brake line) for vapor capture and the passenger side has the fuel delivery line to the engine. There should also be a third hose for fuel overflow from the fuel filler neck to the rear of the car where it empties on the ground. This one is very near the passenger muffler.
Lastly, for the EVAP system to work properly, you need a non-vented gas cap. It should say on it what type it is.
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fuel leak at tank
