help needed for rear caliper rebuild kit - '99 a4 quattro

[Carl Dawn and Katie]

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howdy all,

i was under the car yesterday doing the rear brake pads and noticed that the piston dust boot was torn pretty bad.  The piston went back in without much wrestling so the caliper is still salvagable.

where the heck can I get a rebuild kit for the rear caliper?  did a search on the web and did not turn up much.  oh yeah, it is a '99 2.8q avant.

thanks in advance
carl
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