gas filler hose ? at the pump you mean ?

The evap is to catch fumes from expanding gas when it heats up while in your tank.

 

At the gas stations...............I know

 

.. and well beyond that.
Park your car in the hot sun for a while and it will expand.. a lot. All these fumes have to go somewhere.

Put a can of gas in the sun with the cap tightly closed. It will swell up like a balloon and when you open the cap it will release a lot of fumes.

 

Expansion 101.

 

does anyone know why the bypass valve would fail and begin leaking coolant out the holes on the bottom? just replace it?, or is there a larger problem causing this ?

 

1. It's plastic and cheap.

2. It gets the hottest water the plastic can "safely" handle 100% of the time.

3. If it fails you won't know how to replace it (Ford hopes) and you will take it to the dealership and either trade it in or better yet spend a ton of money on something simple.

4. It's plastic and cheap (Yes this bears repeating).

 

Did we say just change it?

 

flushed, changed, and appears to be working well. thanks.

 

Nice writeup.