Cydrome Leader wrote:
Christopher Tidy wrote:

Chuck Sherwood wrote:

All the broken pumps I've seen were neglected and ruined on the pump side,


What are the important clues to look for when buying a used pump?

Here are a few things to look for. Some of these you can only check if
you can see the pump in person, but that's always a good idea if it's
nearby.

* Check out the general physical condition: does the pump appear to have
been looked after well or is it knocked around and covered with grime
and rust?

* Ask the seller what is has been used for. If it has been used in
industry for neon sign manufacture or air conditioning servicing it will
probably have seen much heavier use that if it was used in a school
science laboratory.


And probably in better condition as it was used recently and when it was used it probably worked. Unuse is worse for a pump than use. Every pump I got from a school was is poor condition because they never use them enough or change the oil.

I've never seen a HVAC pump at the pawn shop that had dirty looking oil in it. They were all working just fine before getting lifted. Stuff at schools sits around and rots forever.

Obviously there's a difference of opinion here. I personally don't see
that there's much harm that can come to a pump if it's left unused,
provided that it doesn't contain water and that it isn't left with the
inlet open so that it can fill with dirt. It's just like leaving an
engine filled with oil for years; I don't think it will do any
irreparable damage. One pump I had from a laboratory which had been
standing for a year or two (and DID have some water in it) was a bit
stiff at first but after an oil change and a few rotations it was fine.
When I dismantled it there wasn't any appreciable corrosion either, just
a very slight discoloration where the rotor had stopped. I think
abrasive dirt is probably the biggest cause of pump damage. But in
general these belt-driven pumps are very rugged and reliable.

Chris