On Mon, 10 Nov 2003, Ben huot wrote:

> Well, of course if the pump is dead (basicaly impossible!)the pressure will
> rise. (Heat up = pressure up) Pump are design  to "wear out", they are
> "coolant lubricated", when one of the seal/bushing slowly fail, by design,
> there is a small openning that let a small stream of coolant out, this is
> sign that the pump is going away. If by any bad chance the pump would
> completely failed (mechanicaly break), the belt would slip or break, the
> alternator light would go on and you would hear a very hissy sound.

There *is* one other failure mode.  I know of a couple of people who have
had the vanes corrode right off the impellors of water pumps.  The pump
spins just fine but the coolant doesn't go anywhere!  I think it takes a
serious lack of cooling system maintenance to reach this point.  One of
the cars (a Honda) had been run on straight water, so there were basically
no anti-corrosion chemicals in the cooling system.

David Brodbeck, N8SRE
'82 Diesel Westfalia
'94 Honda Civic Si -- For Sale
'86 Volvo 240DL wagon