GM water pump

[Martin Powlette]

Ok Greg sorry I haven't noticed this one, I will keep my eyes open next time.
Today I stripped the pump that lasted 1 1/2 days The ceramic seal doesn't look
as bad as the one on the pump with the bad hub and fan clutch, but boy is the
copper side worn out almost as if there was an abrasive agent between the two
and a constant pressure keeping them together. There is even slight feathering
of the copper material on the side of the ring.  The gasket/pressure theory is
no longer now  Tommorrow I will add a descaler and rust remover to the coolant
and flush out the system complete. The customer has lost all his patience and
is upset now, seeing that I have already cost him 2 pumps and now a third to
replace it.  Its at this point you wished you hadn't taken the job.  But where
could this abrasive material be coming from?? "rust" and is that really the
problem???.  or maybe its all a dream.

Martin

Greg Hermann wrote:

> >Thanks Greg at least that is the theory I am working on now.  The bleeder
> >tap is on
> >the top of the pump its a 3/8 drive plug.
>
>  Don't know this engine, but on most, there is also a small air bleed hole
> >> somewhere near the thremostat (usually 1/16 to 3/32 diameter) which lets
> >> air bubble past the stat during initial filling.
>
> I don't think that we are talking about the same bleed hole yet. the LITTLE
> bleed hole is probably under the thermostat horn, right beside the stat.
> Just enough of a bypass to let air bypass a closed stat into the horn and
> radiator hose--it only vents around the stat, not to open air.
> >>
> >> Regards, Greg
> >>