Maybe it only leaks under pressure.  You do have a coolant pressure gauge,
don't you?   :-)
What type of clamps are on that hose?  Screw clamps often need periodic
tightening.
When you replaced that hose, did you use the right type?  Some hose that is
rated for fuel and oil does not stand up to coolant.  It gets hard and
cracks.

Larry A.

On Wed, Sep 4, 2019 at 6:01 AM Roy Nicholl <RNicholl@nbnet.nb.ca> wrote:

> Steve:
>
> It is possible your leak is a crack or at a fitting and when the pipe
> cools and contracts the leak stops (I had a line to the rear cabin heater
> core behave that way a few years ago).  If so, this is an early warning …
> eventually it will just leak.
>
>
> > On 04-Sep-2019, at 02:42, Steven Shelton <shelton4@GMAIL.COM> wrote:
> >
> > We're in Great Falls, Montana, having driven here from Georgia in my 1985
> > 1.9 liter. When we came out of the Lewis and Clark Interpretive Center,
> > there was a steady drip of coolant from under the engine. At that rate of
> > dripping I think there would have been more coolant on the ground if it
> > leaked the whole time we were in the museum. I traced the leak to the
> area
> > around the small hose behind the thermostat housing.
> >
> > I drove into town to get a better signal to see if a vanagon shop is
> > nearby. After being parked for a while I checked again, and there was no
> > dripping. The coolant reservoir is only an inch low. Being late, we went
> to
> > the local KOA ($$$). I just checked and the dirt below the engine is wet,
> > but not dripping.
> >
> > I replaced that hose 7 1/2 years ago. If the hose is leaking shouldn't
> the
> > coolant leak all the time?
>