Gas dripping from gas tank vent on HOT day

Jonnybbad

Petty Officer 1st Class
Joined
Jun 10, 2011
Messages
210
Today the temp is really up there (high 90s :flame:). In the afternoon when the sun was beating on the boat in the driveway ('83 Regal 245) there was gas steadily dripping out the gas tank vent, eating a nice hole in my driveway. I opened the gas cap and a decent little bit of pressure escaped. The tank is full, but not up to the fill neck. Though I filled it up till a bit of gas spurted out the vent at the gas station last time I used it. I put a length of hose down the fill about two feet and it didn't get wet, so it doesn't seem to me that the tank is filled up the neck, therefor I would not think it would be backed up into the vent line, which is about 8" below the level of the fill. Why would this be occurring? Wouldn't pressure escape out the vent and prevent gas from being pushed up and out it? Any thoughts folks?
 

smokeonthewater

Fleet Admiral
Joined
Dec 3, 2009
Messages
9,838
Re: Gas dripping from gas tank vent on HOT day

you overfilled it.... pressure can't escape the vent if there is liquid at the point that the vent meets the tank without pushing gas out
 

Jonnybbad

Petty Officer 1st Class
Joined
Jun 10, 2011
Messages
210
Re: Gas dripping from gas tank vent on HOT day

Thanks for your thoughts smoke. This was my only idea also. I don't seem to really make a lot of sense of this thought though, so I thought I would get some outside input. My logic says that unless the pressure is building very fast it would just slowly burp the vapors past the gas in the line and the liquid would stay put. I do usually fill up on the way out, not on the way in, so that would make sense why this is a new occurrence if this is the cause. Gas prices have been steadily rising around here and I'm trying to pinch a few pennies. I suppose I'll just have to listen a little closer when filling up next time.
 

captain_ron

Seaman Apprentice
Joined
Jul 8, 2013
Messages
35
Re: Gas dripping from gas tank vent on HOT day

My dad's Warhawk used to do that any time it heated depending on was kind of gas cap you have loosen it half a turn after you parking to help relieve the pressure.
 

Jonnybbad

Petty Officer 1st Class
Joined
Jun 10, 2011
Messages
210
Re: Gas dripping from gas tank vent on HOT day

My dad's Warhawk used to do that any time it heated depending on was kind of gas cap you have loosen it half a turn after you parking to help relieve the pressure.

Yeah, that's what I did for the moment. The fill is mounted horizontally on the "tip toe around" style gunwale. When rain comes later this week it will surely find its way in, so considering I've got the outdrive and the trim tab hoses off at the moment for a little work, I may have to siphon a few gallons into a gas can for safe keeping. Thanks Captain.
 

Jonnybbad

Petty Officer 1st Class
Joined
Jun 10, 2011
Messages
210
Re: Gas dripping from gas tank vent on HOT day

Being that all you guys are a dirty bunch. Here's just a tiny peek at some dirty old boat porn. Not too much, just a little nip slip. :pound:
20130716_222534.jpg20130716_222419.jpg
 

MH Hawker

Vice Admiral
Joined
Jul 13, 2011
Messages
5,516
Re: Gas dripping from gas tank vent on HOT day

My suggestion is not to fill it up until its ready for use. That wont help you at the moment though, but next time around.
 

Jonnybbad

Petty Officer 1st Class
Joined
Jun 10, 2011
Messages
210
Re: Gas dripping from gas tank vent on HOT day

My suggestion is not to fill it up until its ready for use. That wont help you at the moment though, but next time around.

Yeah, that's what I was thinking. Thanks for your thoughts James.
 
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