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HELP HELP!! tank pressure!!

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Old Jul 28, 2007 | 04:28 AM
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Default HELP HELP!! tank pressure!!

ok, so my vent hose is sparying gas out of the tank. i start driving and after a short time it starts coming out. if i leave the car running and get out and take the gas cap off it stops coming out of the vent. i understand it releasing the pressure. what i dont understand is why there is so much pressure that it is coming out the vent hose.

ricks hot rod gas tank with in=tank pump. using a vette filter/reg. and this is a 72 camaro with an ls6

any help would be great!!!!!!!
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Old Jul 28, 2007 | 06:06 AM
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this sounds like what my setup will be so i'd like an answer to this problem too. thanx joel
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Old Jul 28, 2007 | 08:28 AM
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are you using a vented fuel cap. If not pick one up
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Old Jul 28, 2007 | 12:07 PM
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i went and got a cap that said vented on it. but it seems to just have a vent button on it to allow u to vent before opening. most local auto parts carry these??


so then would i just plug my vent hose? or leave it?
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Old Jul 28, 2007 | 03:06 PM
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It sounds like the vent tube is run too far down inside the tank. It's sticking all the way down in the gas. It needs to be attached so that only fumes and/or pressure can escape. Is there anyway you can take the tank out and shorten the tube, inside the tank?
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Old Jul 28, 2007 | 04:28 PM
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also maybe a check valve of sometype might keep the gas in and let the vapors escape.
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Old Jul 30, 2007 | 01:18 PM
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Between here and Team Camaro I think I've made this speech at least half a dozen times in the past month...



It's spewing gas because you didn't put a check-valve on it. If you have a vented gas cap, then you should cap off any vent tube on the tank. Gas tank vents are supposed to be ONE WAY! Air is supposed to come in through the vent, gas vapors are NOT EVER supposed to leave through the vent. In old cars, it is normal for the tank to build up pressure--it's NOT a problem. On the other hand, if you are leaking pressure somewhere and allowing gas vapors to escape into your garage (like your vent line does now) , THAT is a HUGE PROBLEM.


Modern cars use an EVAP system with a charcoal canister to store gas vapors and then vent them into the running engine. The gas vapors are NEVER vented directly to atmosphere. The purpose of the EVAP system is so you don't get a big whoosh of gas vapor escaping when you take off your gas cap to fill up.
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