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Old 03-17-2015, 08:36 AM   #1
jabos
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gas leaking out of carb after engine shut off

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The carb had done this last fall a little and stopped during the winter when i would drive it and now it has started again, not sure why and any thoughts
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Old 03-17-2015, 08:37 AM   #2
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Re: gas leaking out of carb after engine shut off

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it leaks on this side also
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Old 03-17-2015, 09:18 AM   #3
hamjet
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Re: gas leaking out of carb after engine shut off

http://67-72chevytrucks.com/vboard/s...d.php?t=663614 As these fellers said, it's probably a stuck float from dirt or something in the floats needle seat. Did you check it?
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Old 03-17-2015, 09:32 AM   #4
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Re: gas leaking out of carb after engine shut off

No I have not checked yet but it has done since I got the truck running and i had the carb rebuilt. The truck sat for about 10 years so I replaced the gas tank all the lines and fuel pump and had the carb rebuilt, it seems to do it when the weather is warmer and after I have driven it awhile.
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Old 03-17-2015, 09:50 AM   #5
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Re: gas leaking out of carb after engine shut off

Replace your gas cap with a vented one.
Could be just built up pressure in the tank.
Next time you take it for a long drive, just pull the cap off. If you hear a sucking or whooshing noise, then you know it's the cap.
To check if it's the float being too high just look in the carb while it's idling. You shouldn't see any raw gas. If you do, then you need to lower your float level.
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Old 03-17-2015, 02:45 PM   #6
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Re: gas leaking out of carb after engine shut off

how do you lower the float? and i know the tank builds pressure because it does a wooshing sound every time i take the cap off. i did run it with out the cap for a few minutes and when i turned it off it started leaking a gain.
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Old 03-17-2015, 04:04 PM   #7
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Re: gas leaking out of carb after engine shut off

The carb should probably be rebuilt. There may be a bad gasket or bad well plug also. To answer your float level question, there is a tab on the float that needs to be bent up. Take the carb off. Take the top off of the carb. Flip the top of the carb upside down. Measure from the carb top to the float. Depending on what your float looks like this pic may help. If you are going to do this, get a carb kit and do the whole thing, you're almost there anyway.
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Old 03-17-2015, 04:34 PM   #8
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Re: gas leaking out of carb after engine shut off

i had it rebuilt in the fall, so do you think i should do it again? the thing i dont understand is that it doesnt leak when the weather is cold but since we are getting warmer weather it starts leaking again. it did leak in the fall also
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Old 03-17-2015, 05:17 PM   #9
Longhorn 70
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Re: gas leaking out of carb after engine shut off

Is this what it was doing before you had it rebuilt or something new?
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And let us not grow weary of doing good, for in due season we will reap, if we do not give up. Gal 6:9
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Old 03-17-2015, 05:24 PM   #10
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Re: gas leaking out of carb after engine shut off

I'm guessing you have the wrong gas cap for your tank. A sealed type cap will hold and build pressure in the fuel system as the temps rise. When you loosen your gas cap do you hear the pressure being released? If so, go with a vented gas cap.
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Old 03-17-2015, 05:29 PM   #11
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Re: gas leaking out of carb after engine shut off

I bought the truck in october 2014 with the truck not running and i put in a new gas tank and sending unit, new fuel lines and fuel pump and had the carb rebuilt and it started right up.it did leak a little after i would shut it off in the fall and during the winter months it did not leak any and now with the weather warming up it has started to leak again. I dont know if the temp as anything to do with it but it does seem to leak more now than in the fall.
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Old 03-17-2015, 05:30 PM   #12
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Re: gas leaking out of carb after engine shut off

I did try letting it idle with out the cap for a little while and shut it off and it still leaked
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Old 03-18-2015, 09:43 PM   #13
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Re: gas leaking out of carb after engine shut off

Shouldn't the tank develop a vacuum during operation, therefor negating a leak due to excess pressure?
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