I put what looks like to be an identical constant tension clamp on my coolant radiator 1" "in" connection last fall. I had a small drip when the temp went down to - 5 F or so. That clamp seems to have fixed the issue ! They are expensive as well as heavier.

I did find 1" auto spring clamps and changed all the other 1" and as well as the 17 mm connections to spring clamps at the last 5yr rubber replacement with good results = no drips , except for that one connection at the radiator when it got real cold.

I got all of the non rotax size spring clamps at Den Paul auto parts. In Canada