hey joevr5 Disconnect your heater hoses from your firewall. Plug them with some thing solid. Cut a broom handle wittle the ends to fit that ussually works. Pipeclamp them into the ends of the hoses to resist your engines cooling system pressure and to stop leakage. Crank your engine and watch for your original leakage. No leak?

Just go down to your local autoparts store and buy a radiator stop leak product that is compatable with anti freeze. About 6 or 7 dollars. FOLLOW THE INSTRUCTIONS and you should be ok. If you want you can just add the stop leak w/o removing any hoses. But you can see for sure if your heating system is leaking or not before you buy the stop leak. I wouldnt put anything but antifreeze into my cooling system unless needed.

I just treated my 97 ranger heater core this way and it worked.

I just priced a heatercore replacement job at 2 local shops. They claimed 7 hours of labor at $700 because they said the dash had to be removed.