Fuel tank pressure.

[stevenscoffee]

Hello everyone. I have a bit of a head-scratcher here.

I have a 1985 f150 short bed with dual tanks. The font tank seems to be overly presurized.

No pressure comes out when I take the cap off to fill, but it will not take fuel!

Also have a small pin hole in the fuel fill pipe. This hisses and spits gas out and leaves a small pudle of fuel.
Reminds me a hole in a tire!

The rear tank hasn't had any issues at all.

Thoughts?

[Gary Lewis]

Several thoughts...

First, the fuel selector valves are notorious for pulling from one tank and returning to the other.  So your front tank may be so full that it can't really take any more gas.  So has your gas mileage gone away?  If so, that might be the problem.

Also, has the tank or filler neck been replaced or removed at some point?  There's an outer and an inner hose and if they aren't put back correctly then you can get a situation where it won't want to let gas down.

Either condition, meaning a bad valve or the hoses put together incorrectly could cause problems with filling.  But if you have a leak in the filler pipe you have a problem there even if you also have a problem with the valve.