It's hard to see, but that does look like a coolant hose. If it's a straight hose, all you need is a piece of 16mm coolant hose (or 5/8"). Also check if the hose clamp is still ok, I can't see if there even is a hose clamp on?
The routing of the hoses do look different than the 1FZ-FE's that I know, so i'm 100% it's a coolant hose. I'm also not near my truck, so can't double check.
What's the colour of the fluid?