rebuilding UFO Calipers

Bernie Benz b.m.benz at
Mon Aug 26 21:06:48 EDT 2002

The piston holds the dust boot in place in the caliper cylinder head, so the
boot must be seated in place before inserting the piston. To do this,
stretch the boot over the OD of the piston as you insert the piston into the
in place boot and cylinder.  Just like G60s or any other caliper assy.
Trial and error, keep trying.


> From: Peter Schulz <peschulz at>
> Date: Mon, 26 Aug 2002 21:41:54 -0400
> To: Bernie Benz <b.m.benz at>
> Cc: 200q20v <200q20v at>
> Subject: Re: rebuilding UFO Calipers
> Ok Bernie;
> Call me frustrated, but I'm having a %#%#@% time trying to get the caliper
> piston dust seal back into the caliper body....I removed the seal, caliper
> piston, etc, cleaned same, reinstalled the dust seal on the piston first, then
> reinserted the piston into the caliper body.
> Having a wonderful time trying to get the dust seal lip inserted and seated in
> the caliper body.
> Is there a secret handshake?  Do I need to perform an incantation?
> Thanks!
> -Peter
> ps> anyone have a part number for the dust seal ( mine has a small tear - from
> BEFORE I started servicing the caliper)
> At 08:10 AM 8/21/2002 -0700, Bernie Benz wrote:
>> IMO, you should have overhauled the UFO calipers also before flushing fluid.
>> With calipers off, put a strip of wood in front of piston across caliper so
>> piston won't fly when you blow it out with air pressure.  Clean internals
>> and rubber seal and boot with IPA.  Lightly polish piston OD with 600 grit
>> paper.  Reassemble, relube guide pins.
>> Bernie
>>> From: Peter Schulz <peschulz at>
>>> Date: Wed, 21 Aug 2002 10:47:25 -0400
>>> To: Bernie Benz <b.m.benz at>
>>> Subject: rebuilding UFO Calipers
>>> Bernie:
>>> Slowly getting 200 #2 (grey) to be roadworthy.
>>> I serviced the rear calipers ( total diassembly, cleaning, grease of guide
>>> pins and e-brake mechanism), Royal and I performed a total system flush
>>> (pressure flush with two liters of new fluid, bled all the lines)... Front
>>> pads and UFOs new, but a bit pitted from non use.
>>> Pedal still feels soft -I know that I need to do some hard repeated braking
>>> to
>>> get the pads and rotors to clean up. but I should probably also disassemble
>>> the front calipers and clean and service them, also...
>>> any tips other than those in Bentley?
>>> -peter
>>> Peter Schulz
>>> 1990 CQ
>>> 1991 200 20v TQW indigo mica
>>> 1991 200 20v TQW titanium grey
>>> Chelmsford, MA USA
>>> peschulz at

More information about the 200q20v mailing list