Bulent wrote: I also think if the pulley is made larger
to slow down the RPM of the pump will be beneficial.
On the down side when the air pumps fail, they lock up.  I noticed an
air pump on 20B with electric clutch, which can help in case of pump
lock-up?

charles harbert wrote:

Bulent, I too use the stock vacuum pump, but find that at low rpms (<1000) the
vacuum drops to below 5", so I would not slow the pump down any further. Even at
the lower vacuum, my guages work fine. If the pump did lock up, I think the
v-belt would break. It could get entangled with the alt/water pump belt, but
probably not. I guessI don't see it as a major exposure. I've had electric
clutches (air conditioning) fail (mechanically and electrically), so that may
not be a foolproof answer.

 
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