[s-cars] Front rotor replacement

[Jerry Scott]

Here's a write-up that I did last year on brake pad replacement.
Jerry Scott

Audi 93 S4 Brake Pad Replacement

Jerry Scott, 09-30-02



1.     Put the car on four jack stands and remove wheels.

2.     Starting with the rear brakes, remove the caliper bolts with an
8-mm socket allen wrench.

3.     Put two lug bolts into the rotor to hold it to the hub.

4.     With two heavy screwdrivers, pry on the caliper at the rim of the
rotor until the caliper comes off.  Support the caliper with a wire to
keep the weight off the brake line.

5.     Remove the old brake pads from the caliper and remove the rotor.

6.     Attach the caliper back in place with one bolt.

7.     Using needle nose pliers, turn the caliper piston clockwise until
the piston is flush with the seal.

8.     Remove the caliper again and put the rotor back in place and hold
with two finger tight lug nuts.

9.     Drill out the copper rivet for the spring in the old pads and
save the anti-rattle spring.

10.  Attach the anti-rattle spring to the new pads by using a .187 in.
dia. x 7/16 in. closed end aluminum pop rivet with two stainless steel
#10 washers on each end of the rivet.

11.  Put the new pads with springs attached back into the caliper and
remount the assembly back in place.  Torque the two allen head bolts to
80 ft-lbs.

12.  Pull the emergency brake lever several times to adjust the piston.

13.  Remove the two lug bolts from the rotor and replace the wheel.

14.  Torque the lug bolts to 85 ft-lbs.

15.  Remove the front wheels and remove the two-caliper mounting bolts
with a 17-mm socket wrench.

16.  Support the caliper with a wire to the sway bar.

17.  Remove the spring retainer from the outer pad with a torx wrench by
removing the two 6-mm bolts.

18.  Put two temporary lug bolts into the rotor to hold it to the hub.

19.  Pry off the caliper in the same manner as the rear calipers.

20.  Disconnect the wear sensors by squeezing the wire retainer and
separating the connector. Then lift the plastic tab on the lower half,
and rotate the connector 90 degrees to remove it from the bracket.

21.  Remove the pads from the caliper.

22.  Remove the top springs from each pad with a 3/16 punch and hammer
gently applied on the edge of the rivet. Slide them onto the new pads.

23.  If the new pads do not have an electronic wear sensor, cut the wire
from the old pad 2 in. from the connector), strip the ends, then solder
the ends together.  Apply liquid vinyl insulation sealer.  This
connection will prevent the brake dash light from coming on.

24.  Make a paper template from the old pad for the location of two
holes for the spring retainer.

25.  Drill and tap two holes on the outboard pads only.  The tap size is
6 mm x 1.0 bottoming tap, and the drill size is: 13/64 in. Set a stop on
the drill press so that you only drill about 1/16 in. past the insert
thickness. This allows room for the tap to bottom in the hole and still
cut a full thread in the insert.  If you do not have a bottoming tap,
grind the point off a standard tap.

26.  Pull off the sliders and lubricate them with white grease. Slide
them back into place and reconnect the bellow seals by lifting the seal
over the edge of the lip then turn the seal to engage it all the way around.

27.  Insert the new pads into the caliper and install the outboard
retainer spring with the stock 6-mm bolts into the two newly tapped
holes.  Make sure that the slide is full compressing the rubber bellow
seals.

28.  Attach the caliper to the spindle with two bolts and torque to 85
ft-lbs.

29.  Remove the two temporary lug bolts holding the rotor.

30.  Bleed the entire hydraulic system and replace the wheels; torque
the lug bolts to 85 ft-lbs.

31.  Remove the car from the jack stands.

32.  The red emergency brake light may come on after the installation.
If so, turn on the ignition with the engine off, then push the left dash
button that sets the clock to run a diagnostic test.  It will cycle
through the tests, then will say OK if everything is working correctly.
This should turn off the light.