Radiator aux cooler: Leaking fittings

WesternHorizon wrote:
1995 Tioga Montara Class C on a Ford E-350 chassis, 460 V8, E4OD transmission

Has recently started weeping fluid at both connections to the auxiliary cooler. Just a few drops have slid down and are hanging on the line that runs horizontally below and behind the radiator. No detectable drop in fluid level, yet.

It looks like you're correct that it's actually just a rubber hose clamped onto a barbed screw fitting. As such, you have three points of failure. If the hose is original, it may be sweating. Even if not the hose, if original, time to change it out. The second point is the hose to connector with the clamp. As with any mechanical clamp, the hose could now have gaps allowing fluid to escape regardless how tight it is. The last location is the connector to the cooler and the O-Ring could be worn.

Also having an older unit, I found the most likely culprit on those flexible hoses are the hose itself. Sweating is an early warning sign of a impending failure. A Motorcraft KM1938 hose and a set of Hayden 394s will run about $45 and easy to replace. Cheap to replace everything with new, so don't put it off too long as hose failure is never pretty.