re: hydraulic pump (bearing?)

[Phil Rose <pjrose@servtech.com>]

Recently, Mike asked:

>Date: Sun, 2 Aug 1998 10:12:03 -0400 (EDT)
>From: Mike Mulholland <meyeke@netinc.ca>
>Subject: hydraulic pump
>
>i took apart my failed hydraulic pump...i figgered what the heck it's broken
>anyhow! much to my surprise it was like new inside and the only failure was
>the front bearing. have any of you had experience changing the front bearing
>on a pump? igor?? since i stole the replacement form the 5ksw i'd like to
>get it running again and if i can replace the bad bearing and put in a
>rebuild kit it should be the least expensive route....btw does anyone have
>the part number for the rebuild kit?

Igor responded that, having done a number of hydraulic pump rebuilds, he
had not yet come across any pumps with bad bearings.

The new noise that has started to emanate from the front of my '91 200q
engine causes me to wonder if it is typical of a sick hydr. pump, and if
so, could it the sound of a complaining _bearing_?

What noise? It is a  medium-high-pitched "chirp-chirp" that is be coming
from the front end--near or at the pump. But I've heard tales about _water_
pump "chirping", so I don't rule that out (timing belt and water pump were
replaced by dealer 20K miles ago. The hydr. pump is a Shokan rebuild with
less than 20K on it.

BTW, if I grab the hydr. pump pulley and tug on it (in/out), it has some
noticeable play--perhaps 1/32" or so, maybe a bit more. Don't know if that
indicates anything amiss. When I bought the car, I noticed that the hydr.
pump drive belt was considerably tighter than the one in my old car. With
the old car, my mechanic had the philosophy that the hydr. pump belt was
best left relatively slack because otherwise the bearings will get eaten.
Is my "new" '91 suffering from an overtightened drive belt I wonder?

Is it possible that loosening the belt at this point would "cure" a
complaining bearing?  Igor stated that "If the pump is roaring, most of the
times it's due to an overtightened belt." Of course that statement doesn't
necessarily imply that the effect of an overtightened belt is reversible.
How about it, Igor? Yet "roaring" and "chirping" seem like very different
things.

Thanks for any comments.

Phil

Phil Rose		Rochester, NY
'89 100
'91 200q		pjrose@servtech.com