Heater Plumbing

[wmah]

You may be able to hose a piece of 3/4 inch hose to cover the pipe on the heater core and slide the 1 inch hose over it, maybe. I also believe they sell adapter hoses that do it this way I remember seeing them once before when I was doing this on o bus. Another option is to go to your hardware store and find some brass fittings that will make the adapter you need.

[Coma]

Brass fittings will handle your needs.
Here you can find whatever you need.
http://www.ppe.com/pdf07/0263-0265.pdf

If not on that page, go to the main index page http://www.ppe.com

[Coma]

Nothing is required or suggested on the barb side. Just a good clamp. What you are experiencing is a result of old age.