How to Change Front Brakes on an 1998 Audi A6

1. Open the brake master cylinder reservoir's cap, and siphon out about half of the brake fluid in the master cylinder reservoir, using a clean turkey baster. Transfer this fluid to a small container.
2. Loosen, but don't remove, the front lug bolts. Raise the front of the A6, using a floor jack, and position jack stands under the vehicle's subframe. Lower the Audi onto the jack stands. Remove the lug bolts, and pull the front wheels off the Audi.
3. Pry the protective rubber caps off the caliper pins, using a flat-head screwdriver. Note the position of the outer brake pad retaining spring -- the thin wire spring -- securing the outer brake pad. Pry the retaining spring from the caliper, using a flat-head screwdriver.
4. Find the brake pad sensor wire -- the thin wire running from the inner brake pad. Trace the wire upward until you locate where its wiring harness connects to the Audi's wiring harness. Press the locking button on the Audi's wiring harness and unplug the brake pad's wiring harness from the Audi's wiring harness.
5. Remove the two caliper pins using a ratchet and a hex-bit socket. Pull the caliper up and off the caliper bracket, and hang it from a nearby suspension component, using a bungee strap. Pull the outer brake pad from the caliper bracket.
6. Position an 8-inch C-clamp over the caliper so the fixed part contacts the rear of the caliper and the screw part contacts the old inner pad. Tighten the C-clamp until it stops moving. Remove the C-clamp from the caliper. Insert the blade of a flat-head screwdriver under the inner brake pad and pry it upward slightly, then pull it from the caliper -- notice metal 'fingers' on the rear of the pad insert into the caliper piston.
7. Loosen the two caliper bracket-retaining bolts, and pull the caliper bracket off the steering knuckle. Grab the brake rotor and pull it off the front hub. If the rotor does not pull off easily, lightly tap the rear of it with a rubber mallet to free it.
8. Inspect the brake rotor for any defects, including: cracks, hot spots, grind marks or deep grooves. Replace the rotor with a new one if defects are present. Set the rotor back on the hub, lining up the lug bolt holes on the rotor with those on the hub.
9. Set the caliper bracket back on the steering knuckle, and hand-thread the caliper bracket-retaining bolts. Tighten the caliper bracket-retaining bolts to 96 foot-pounds, using a torque wrench and socket.
10. Slide a new outer brake pad into the caliper bracket. Line up the fingers on the rear of the new inner brake pad up with the cavity in the caliper piston. Press the pad onto the caliper piston until the fingers are inserted fully into the cavity.
11. Remove the brake caliper from the bungee strap, and set it on the caliper bracket. Hand-tighten the caliper pins, then torque them to 18 foot-pounds, using a torque wrench and hex-bit socket.
12. Slide the outer brake pad-retaining spring back into its position. Compress the retaining springs hooks with your fingers and insert the hooks into the two holes in the caliper. Release the hooks to lock the spring in place. Plug the brake pad sensor wiring harness into the A6's wiring harness.
13. Repeat Steps 3 through 12 to replace the pads on the other side of the A6.
14. Reinstall the front wheels onto the A6's front hubs, and hand-tighten the lug bolts. Raise the Audi off the jack stands, using a floor jack, and remove the jack stands. Lower the Audi to the ground and tighten the lug bolts -- in a crisscrossing pattern -- to 90 foot-pounds, using a torque wrench and socket.
15. Press and release the brake pedal until it feels firm. Check the brake fluid level in the master cylinder reservoir, and add DOT 4 brake fluid until the level reaches the 'Max' line on the reservoir.