hd4unm -
Thanks for the suggestion. However, the heat control valve on my AD truck is not mounted in the heater like it is in your TF truck. It is mounted on the firewall separate from the heater and would not cause the leak that I am experiencing.
> CLICK - Ranco valve on passenger side of firewall. You can see one hose from the engine to the heater and one hose from the engine to the Ranco valve, then another hose from the valve to the heater.