I really like it when posters end their threads with a solution so here is what I did and what it was.
I crawled underneath and took each flex line off one at a time and capped the connections. I got to the last one going to the rear furnace and that was it. The flex line goes from the manifold pipe on the curb side frame rail over the transmission, back over the radiator, up through the floor and into the burner compartment. I was going to pull it all out and replace it, but in the process I found a 1/4 inch "chew" hole right above the radiator. I cut out the bad section and inserted a repair coupler, tightened the clamps turned on the main valve, soaped it up to look for leaks. All is well and everything is working.
Thanks to all who responded.
Dave