Fuel tank question

[NEUTRON]

Late last week I came home to the smell of gas
coming from my car port/boat, fuel was bubbling
up from the gas tank fill cap. Anyone had this happen before. How much space should you allow in warmer temps for expansion. Not a good situation.

[Pilar]

Neutron, this is pretty common. You filled it cold and now in the spring the temp is going up.

My 42 gallon tank holds only about 40 in the summer. The vent on your tank should shut off the gas pump at the right level. Try filling your tank at full flow. The backpressure from the vent will trip the pump before you overfill.

I estimate the expansion to be 5% for a 30 degree change. This effect is especially noticeable on a 50 plus gallon tank.

[ 05-20-2002, 11:27 AM: Message edited by: Pilar ]

[AngleThis]

The expansion you are referring to is probably due to an air pocket which has warmed up and increased it's volume; fluid doens't expand like gas does. More than likely, you just need to "burp" your tank. If your boat's pickup, fill, and vent nozzles are at the stern of the tank, just point your bow down (drive down a hill, fold the trailer jack, etc. You might also find that after you do your fuel gauge reading also drops. I have found that if I don't angle my bow down when filling up, I top off at about five gallons short due to this air buble at the front of my tank.

[Doubletake]

********* hit it on the head. I have also come home to gas bubbling out of my boat when the sun started coming out again last year. The warmer weather expanded the air in my tank, (95% full), and was pushing gas out on the ground. I lowered the bow, let the air escape and good to go.

Doubletake

[Mofish]

What kind of boat do you have??

[Doubletake]

19' Thunderjet

[Thumper]

Sometimes I lower my bow and vent the gas too (see avatar). Works great. Just like on a boat.

[ 05-21-2002, 05:38 PM: Message edited by: Thumper ]