Re: [DML] Water pump pulley came off on its own

["checksix3" <jetjock11@xxxxxxxxxxx>]

You can't use a bolt on pulley, it needs a different pump.
You have several options, all of which involve removing the pump.

If the pulley is worn you can rebush it and re-press and then pin it
at right angles to the key. It'll give you many years of service if 
done right and will prevent you from having to toss a pump with low 
time in service.

Buy a new pump with a bolt on pulley. The only thing this gets you is 
less hassle down the road when it comes time to replace it again.

Buy a new pump with a new pressed on pulley.

No matter what you do, be advised that with the pulley backed off 
you're going to destroy the rear of your pump. The instructions on wa 
well known tech note state the pulley must be pressed to a specific 
dimension on the shaft and no more.

This is incorrect. The pulley must be pressed all the way until it 
seats against the bearing race and preloads the shaft seal, the 
dimension just happens to be what the author of the tech note found 
when he measured the old pump. There is a reason for that dimension, 
it's all the way down. In other words you need to press it until you 
can't go any further.

This is because the rear of the pulley is used to preload the ceramic 
face seal in the pump. If the pulley backs away from the outer 
bearing race the the shaft will drift to the rear causing the seal to 
unseat and allowing the impeller to contact the rear pump housing. 
Ignore the specified dimension in the tech note and press the pulley 
all the way and leave the rear housing off to check for zero fore and 
aft movement of the shaft when done. The specified dimension should 
come out the same but don't rely on it as a stopping point.



 
> >    I've acquired another car which I'm restoring, and the pulley 
on
> the
> > water pump has creeped off of the shaft. It's now out to 
> > where it's over
> > half an inch off of the shaft. The belts won't stay on at such an
> > extreme angle. I've never heard of this happening. It didn't 
happen
> > quickly and the pulley seems to be solidly on the shaft. I'm 
> > told it's a
> > 2 year old Grady pump.
> > 
> > Ken
> >




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