Rad is about 14 months old and I haven't been dumping anything in it.
I checked the belt for both condition and tension before I left ---
both were good. When I had the belt off I checked the water pump and
it spun freely.

Cheers,
Doug

On 8/24/05, John Bange <jbange@gmail.com> wrote:
> > The rad's only about 14 month's old --- I'd hate to think it's hosed
> > so soon. Is there any way of testing it?
> >
> 
> Radiator ought to be fine, unless you've been dumping in stop-leak or
> something. Time to sit back and think about the possible points of
> failure. Cooling as all about water flow. If the water doesn't flow,
> it doesn't get cooled fast enough. Water pump is worth casting  a
> suspicious eye upon, since your belt broke. I don't know what
> condition the belt was in, but it seems like an awfully interesting
> coincidence. If the pump's dragging, not spinning fast enough due to a
> failing bearing, that would certainly reduce your water flow and could
> put enough strain on the belt to kill it. Your pump must be at least
> partly functional, though, as the addition of the heater  brought the
> temperature down. If the belt hadn't failed, my suspicion would fall
> first on the thermostat.  A bad thermostat will block flow through the
> radiator, but not the heater core (which is independent of the
> radiator circuit). I'm bettin' the fan switch and radiator are fine
> and the water just isn't getting up there. Might be worth trying a new
> thermostat first, as it's easier to do than change the water pump.
>