On Fri, 6 Jan 2006 12:26:09 -0000, Set Square wrote:

Anyone know why this is? Does a pump rely on water to cool it -
albeit using 'coolant' at 80-odd degrees? Or is water needed to
lubricate the bearing in some way?

AFAIK it's mostly the lubrication of the bearing(s). Way back before I
understood things I fitted a pump but didn't bleed it. It failed
within 18 months, maybe less than a year. The replacement I bled
(RTFM...) and that one hadn't failed when I sold the place a few years
latter.

TBH I can't see much advantage to testing before installation. After
all you'll have just fitted it so the isolation valves will work and
the flanges won't have welded themselves to the pump, bit messy with
the water in the pump but that is all.

--
Cheers
Dave. pam is missing e-mail