Where to find part # to this hose?

[Waterloo]

I have a metal pipe there, that is more than likely a Freightliner part. I would drain off the coolant and remove the hose. Take it up to NAPA or FleetPride if you have one near you that can match the hose physically with something in stock. If you can match the bend and hose I.D. just cut to size.

Or, you can make your own if you need a true 90* bend, use some brass pipe nipple and a brass 90* pipe fitting with heater hose. Should be able to find those parts at Home Depot, Lowes or any good hardware store. That is, if you have the room.