Noisy New Hydraulic Pump

[erict@cta.com (Eric Thorstenson)]

Hi all. Got a question regarding a new hydraulic pump I installed
a few days ago. It's noisy - not a bad bearing kind of noise like
the old one, but just sort of a loud pumping type noise, if that
makes any sense. What I find interesting is that the noise is only
present when the pump is not under load. For instance, when I turn
the wheel with the car stopped and the engine at idle, the pump is
perfectly quiet while I'm actually turning the wheel, but resumes
making noise once I stop.

Installation instructions that came with the pump indicate that you
should use only the stock hydraulic lines, because one of them has
a restrictor in it, without which the pump will be noisy. Bentley
also confirms this, and says to check the restictor as part of the
pump installation procedure. OK, so I'm using the stock lines and
checked the restrictor, which looked fine to me. So the questions
are:
 - anyone know what differentiates a "good" restrictor from a "bad"
   one? Bentley basically just says to check that it's there.
 - could a failed bomb (which I believe I have) cause the pump to
   be noisy, even if the hose and restrictor are OK?
 - is this perhaps a clear (but new to me) indicator of a bogus
   pump? I'd hate to thing a rebuild ought to be bad, but I've had
   wierder things happen...

Thoughts anyone??

Thanks a bunch,
Eric T.     '86 5kS
erict@ra.cta.com