Small rubber fuel line leak at the frame rail.

[darrellyates]

Originally Posted by GMCPaul

Thank the EPA and our government, old rubber fuel hose will dissolve with the E10 ethanol we are stuck with today.
A fix is PTFE style performance hose and the special fittings required to use the hose
The ethanol is also causing steel fuel lines to corrode and will corrode brass & cause lead & tin solder to break down and fail.
Paul Jr @ GMCPauls

PTFE hose is normally just PTFE (commonly known as teflon) in another carrier. PTFE by itself can't be used for a hose, it isn't an elastomer or flexible, so it depends what carrier it's in. Usually, today, it's in a nylon carrier which is an excellent polymer for fuel resistance, including ethanol fuels.

For modern rubber fuel hose, make sure it's Viton rubber. That's a synthetic that's resistant to ethanol. Most are marked as not only fuel line, but E85 compatible (E85 is 15% ethanol, which is the highest commonly manufactured I believe).

This post is correct, ethanol in gas will dissolve most any other rubber including EPDM, and latex based rubber products.

I've even seen radiator hose used as fuel neck connecting hose, and of course vacuum lines used for gas tank vents, and heater hose for fuel lines. Will swell, degrade, dissolve in a matter of weeks not years.