04 F150, This is looking up above where the spare mounts.....
What is this long cylinder for? There's two lines going to it, and it looks like they go to the gas tank?
Thanks, Marc

 

that is your charcoal canister for your EVAP system. Its where escaping fuel vapors are captured, and then later they are safely released into the engine under certain conditions.

incase you are wondering this is what one looks like out of the truck and in 6 pieces

 

Yikes id be worried about the lines in between your bump stop and axle

 

Patman, Thanks for clue-ing me in,
GCW, Thanks for your concern, but those lines aren't in harms way.....
The angle of the photo makes them appear to be...
This area is next up to all be cleaned and painted as I continue addressing the rust issues.
(See my "2004 Rust already" thread)

PS: Patman; What size image is that? I'd rather post smaller photos.
I use the up-load link in Photobucket I believe it automatically sizes
the pictures at 1024x768. Not 100% sure though.

 

i always resize mine to 800x?? and keep the aspect ratio. they are about the same size as the one he posted. i think the photo gallery here automatically resizes larger pics to 800.

 

Yours is 1024 × 766 mine is 800 × 600