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Re: hydraulic pump

Mike Mulholland <meyeke@netinc.ca> wrote:

>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??

Of all the pumps that I rebuilt (4 or 5) none had a bad bearing. BTW, how do you
know that the bearing is bad, Mike? If the pump is roaring, most of the times
it's due to an overtightened belt. If you have the pump apart, check the gap
between the inner central roller and the body with the filler gauge. Should be
<1mm. OTOH when I rebuilt the Brian Armstead's pump, that part was one piece so
there was no gap to check.

> 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? 

Sure. The fiche does not show any, however Audi issued two TSB dealing with it:
A48-89-01 and A48-89-02. Let me know if you need a copy coz I have the
collection of TSB for an '89 200.

1. The full kit is: 026 198 049B - the front seal and all O-rings. First time I
bought it for $18 from Blau, last time it was $38 locally.
2. If you want just replace the big outer (8) O-rings, it's 026 145 049.
3. If your big caps are busted they are: 026 145 541.

Bear in mind that 2. is included in 1. whereas 3. is not. Examine the caps
carefully. What happens is people seldom use the appropriate tool for their
removal and use a chisel instead which damages those cross shaped slits. After
which tightening them to spec (50Nm) becomes impossible.
The socket I've used is a 3/8" drive, looks like a giant flat screwdriver (which
it probably is). I think the blade is 3/4" wide (19mm x 2mm for my fellow Metric
Indoctrinated listers). The whole socket is about 30mm tall. I've gotten it
through my favourite source - the McMaster-Carr catalogue.
Craftsdude has it in 1/2" drive, it's called a "drag link socket". You'll need a
3/4" one, it's catalogue P/N is 44512, they sell it for $6.49.

The rebuild itself is straightforward Bentley (or better yet, per Audi's own
TSB). Just don't forget 2 crucial things:
1. Notch-mark the reference on the pump body with a chisel BEFORE you separate
it in two halves!
2. Prime (pre-fill) the rebuilt pump with the snake fluid by pouring it into the
suction inlet while rotating the rotor by hand! You can do it on the car before
you connect the hoses and put the P/S belt on.

The bearing is not included in either kit.

I once had a roaring bearing in the A/C compressor clutch. The new clutch was
~$140 and I decided to replace just the bearing, rightfully thinking that Audi
was never in business of making their own bearings.
I pulled the clutch off the A/C compressor, took the bearing out of the clutch
and found out that it was made by a Japanese Co. named Nachi. The p/n was
stamped on the separator.
I asked our resident Mechanical Engineer James Marriott for help  and in 24
James found me the source and even ordered the bearing for me. I replaced the
bearing and lived happily ever after with the quiet A/C clutch.

I hope James wouldn't mind if I give out his excellent source for bearings:

Eastern Bearings,
The guy to talk to is Tom Breault, 800-647-3925.

Let me know if I can be of any help with the P/S pump rebuild, Mike.

Igor Kessel
'89 200TQ -- 18psi (TAP)
'98 A4TQ -- mostly stock
Philadelphia, PA