Fuel Lines again

[LSGarage]

I have noticed that when I fill my tank up I smell gas fumes until I burn it down to just under 3/4 indicated. LonghornMan said that there is some rubber under the cab also (I have already replace the bubber from the frame to the pump and it's steel up to the carb). I haven't done any investigating yet its too cold but I'm wonder why I only get the fumes when the tank is full. Is there possibly a tank drain thats leaking only when there is more pressure due to a full tank?

[Longhorn Man]

71/72 have rubber lines up there. If I said the 70 and older had rubber, i was mistaken or havin a brain fart.
THe common reasons for fuel smalle only when filled up...
1 Fuel cap leaking, and a hole in the cab corner.

2 O ring around fuel sending unit leaking. Look for clean streaks int he dust on the tank.

3 Cracks where the filler neck joins the tank, normally on the bottim if the filler neck. This is commonly caused by leaning on the pump nozzle at the gas station. There is no rubber hose to take up any flex like on later model vehicles.

[kaycee]

Does the sender have a good seal on the tank??

[dennislbrooks]

also if you have an aftermarket sender the soldered fitting may be suspect. From my experience thru the years with the fill next to the door--you will always get a wiff from the fill upon entering an exit.

[LSGarage]

OK thanks for the leads, I'll let you know the outcome . . . come spring. HNY