RE: Replacing rotors on '93 90CS

["Perry, Christopher" <cperry@cotl.com>]

Elliot, I have an '89 90q so I'm not positive that your car is the same
but if it is...
You DO NOT need to remove the front axle bolt to replace the front
rotors.  You merely remove the roadwheel, remove the two (17mm I think)
bolts holding the brake caliper on, then either remove a small set-screw
and remove the rotor OR no set screw and the rotor just comes off.  You
will want to make some hangers (out of wire clothes hangers or other
suitable material) to support the calipers and prevent damage to the
brake lines. 

The rear do require you to remove the axle nut but it is relatively easy
 - not torqued as much as the front.  You will remove the nut, a washer,
the outer wheel bearing then the rotor.  If you are replacing the rotor
you will need to either press the race and bearing out of the old hub
and into the new one or buy new races and bearings and press them into
the new hub. Dealing with the parking break cable will be the major PITA
for this job.

 When installing the new break pads the front calipers can be compressed
using a C-clamp and one of the old break shoes but the back requires a
tool (on my car it is an allen wrench) to turn and compress the caliper
piston.  Remove the break reservoir cap and keep an eye on the fluid
level as you do this.
HTH,
chris perry

>-----Original Message-----
>From:	Elliott Potter [SMTP:epotter@abraxis.com]
>Sent:	Wednesday, January 07, 1998 12:08 PM
>To:	quattro Digest; cnewbold@transarc.com
>Subject:	Replacing rotors on '93 90CS
>
>I'm going to need to replace the rotors in the front and rear of my 90
>CS, but am having a little trouble figuring out exactly how (there's a
>first time for everything!)  Looking through the repair manual, there
>are detailed instructions on how to replace the pads, but none on how to
>take off the rotors.  I did, however, find some pictures in the axle
>assembly section that looked promising, but they seem a little too
>simple:
>
>Front axles:  It looks as though there's a single bolt/washer that
>screws into the Axle shaft, through the wheel bearing and wheel hub. 
>Can this be correct?  One bolt?  Also, it says "loosen/tighten ONLY with
>vehicle on ground."  Well this just doesn't seem right--especially if it
>attaches the wheel to the axle!  How is one meant to support the car?
>
>Rear axles:  This looks much more simple, though it is the same idea as
>the front:  There's the Stub axle that attaches to the axle beam, and
>this sticks through the splash guard, inner wheel bearing, rotor, wheel
>hub, outer wheel bearing, etc. and ends with a large nut.  The biggest
>question the illustration brings to mind is that the rotor they show is
>the same diameter as the wheel hub!  It looks like it's in the right
>place but I'm not exactly sure.  At least this one doesn't insist that I
>remove the bolt while the car's on the ground!  Though in this one it
>seems less likely to do damage.....
>
>Elliott