On close examination (w/o wheels off), it appears that the two front rotors on my '91 745 Turbo w/ABS are different - on the passenger's side, the rotor itself sticks out about 1 cm from the hub and appears to be an obvious separatate piece. On the driver's side, the hub and the rotor are flush and appear to be one piece. I need to look into this further, but aren't all the rotors on the later 740's (this one has ABS) the updated two-piece ones?

My brakes shimmy when I brake hard, and I need to check the brakes more carefully. What do I need to look out for when working on ABS brakes? I also will check the FAQ as I know there is an ABS brakes section there. Thanks.
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Darius in Albany NY '86 744 GLE (172K); '91 745T (161K)

Precautions for working on ABS equipped cars:
If calipers or other hydraulics need replacing, leave it to a professional.
When servicing pads, do not turn the car on until it is reassembled. I have heard, though not seen it and do not wish to confirm personally, that the ABS system can pressurize the calipers right at turn-on and eject pistons. I don't want to find out.
Otherwise, replacing pads is easy and straightforward, and likewise rotors.

You *must* have normal 2 piece rotors on both sides. The ABS front wheel sensors see a tone ring that's attached to the bearing hub. The rotor slides over this. Probably just covered with crud and rust.
If you replace your rotors, take a minute to clean off your ABS wheel sensors- removing the grit and filings reduces faults and ABS warning lights. Use masking tape to get the grit off the magnetic wheel sensors.
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Rob Bareiss, New London CT ::: '87 244DL/M47- 221K, 88 744GLE- 202K, 91 244 181K, 88 244GL 145K

I need to take the wheels off and look more closely, BUT, the two rotors are very different - on one the rotor itself does not protrude from the hub, and on the other one it protrudes by about 1 cm. No rust or crud of any kind, just differently built rotors. The brakes work *okay* but not at all as crisply or smoothly as the brakes on my '86 745. Thanks for the input Rob.

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Darius in Albany NY '86 744 GLE (172K); '91 745T (161K)