[kingfish59]

Drove my 1970 chevelle home from car show Sat nite and stopped to fill up with gas. Got home and parked in garage. Next day, extremely strong gasoline odor so opened garage door and let air out. Checked for puddles, leaks around carb and fuel pump with no luck. I'm now into 3rd day and every night i get home i open garage door and strong gasoline vapor odor. Does anyone have any idea what may be causing this???
Thanks in advance for your help!!!

 

[SWHEATON]

Since this only happened with a full tank it could be leaking fuel out top of tank due to a rust hole/s,dried out or schrunken rubber o-ring seal on fuel sender toplate /dohicky,i forgot the dang name for the metal retainer type ring that has that rubber o-ring seal,just slipped my mind at this moment.

Coud also be 1 of the rubber hoses being rotted/cracked that's attached to the top of the tank for fuel sender or fuel evap canister.

Maybe the fuel line is seeping under car someplace too.

Check the oil to ensure the diphram didnt go bad in the fuel pump loading up the crankcase with fuel ,not likely but can and does happen once in a while.

Scott

 

[71 chevlle]

I had purchased a locking cap for my truck and it didn't seal like the one that came on it when I got the truck.During the heat of the day vapors would leak out.Be sure there is a seal on your cap first. If there is maybe the metal tabs that twist your cap down are bent preventing cap from tightening down like it should.Try a new cap.

 

[65cayne]

What Scott said, check underneath the car and around your tank. (seams, hoses, etc...)

 

[Gary S]

Basic physics tells us that gasoline expands when heated. If you filled your tank on a hot day with cold gasoline stored underground, it will expand when it warms up and overfill the tank.
Unless your car has California emissions, it most likely has the old style vented fuel system yet. This system had no room for expansion in the tank, so if you over fill the tank when the gas expands, the extra volume will push up and out the vented cap.

 

[kingfish59]

Thanks for all the comments. After the car has sat for 4 days there is still strong gasoline smell. I had looked initially under the car but just quickly. I made sure the gas cap was sealing off, fuel pump lines, carb, etc with no luck. I looked under the gas tank late last nite and it appears there may be some gas residue. I'm beginning to suspect the top of the tank. The tank is only about 5 yrs old and in good shape from appearance below and on sides. I need to jack up the car tonight and look. Will i be able to see anything without dropping the tank???
I'm tempted to drive it and use up a few gallons just to eliminate the fumes plus a little nervous about any potential fire, it was definitely full when I parked it Sat nite as I only drove 2 miles to get home after filling up. I will first inspect the fuel line around tank, etc tonight.

 

[ss1970chev454]

Have the same issue with mine when the tank is full. Try running the car for 10-15min. When the fuel level drops, the smell will be gone.

My problem is the hard line going into the sending unit has become loose after removing and installing the tank about 40 times in the last 25 years.

 

[SWHEATON]

If you dont have time or good weather to drive car take 5-10mins to simply syphon out 4-5 gals of fuel to stop it from leaking out if top of tankk thrue bad oring seal ,rust holes ,of cracked rubber fueline comming off the tank etc.

BTW,that same thing happened tomy 69 a few yrs back,the original rubber hose that went to fuel pickup cracked and was leaking fuel.

Replaced that small piece of fuel line and fumes were gone.

Scott

 

[kingfish59]

ok, thanks Greg and Scott for your comments. I'm planning on working on it this weekend. I definitely have leak off the top just not sure where and also not sure if just burning couple gallons of gas will do it without further repairs. It's always something! But then I guess I'd have to find something else to repair around the house!

Have a great Labor Day weekend and thanks again to all who posted.
I'm sure I'll have plenty of other issues to resolve. I already know i have a rear window that has a plastic guide roller broken off. So i guess that will be next.

Greg