Changing the front brake pads on the Audi A6 Savant is a relatively straight forward task to complete. The brakes are one of the areas where Audi appear to have taken the wise decision not to over-complicate things too much.
This documentation applies to the 2000 model, but the steps should be similar for others too
Work on one side at a time (but always replace brake pads as an axle set!), and check your work carefully as you go - a brake failure is a serious and unpleasant event to experience!
Step 1 - Loosen the Wheel
The first step is obviously to get the wheel off. Unfortunately they seem to have a nasty habit of sticking to the brake rotors, so it's seldom as simple as undoing the retaining lugs.
So, before you've got the car in the air do the following
- Using the torque wrench slacken each of the wheel retaining nuts
- By hand tighten them back up, before slackening off by a single turn
- Drive the car forwards and turn in the direction of the wheel you've slackened the nuts on
- Reverse back into the work area
- Press down on the suspension a few times, just above the relevant wheel arch
Now Jack the car up, place on axle stands and proceed with removing the wheel. If it's still stuck, a good kick from the underside should now be enough to loosen it.
Note: As soon as you have the wheel off, screw one of the retaining nuts back into the hub - Audi obviously didn't see fit to use an additional screw to retain the brake rotor.
Step 2 - Remove the old pads
Now that the wheel is removed, you should have a clear view of the caliper. The first thing to do is to remove the pad retaining spring with a small pair of pliers. Put it somewhere safe.
Next, we need to loosen things up a little. You should be able to see the edge of the brake rotor and the old pads through the side of the caliper, using the large screwdriver, carefully lever the caliper to push the piston back a little.
The next step is to undo the slide bolts, on the back of the caliper there will be a rubber housing (probably) with a plastic cap on the end. Remove the plastic caps and then evenly slacken off the slide bolts using the Allen key.
Make sure the caliper body isn't allowed to fall if it suddenly comes loose (you don't want to damage the brake hoses).
Carefully slide the caliper body away from the old pads, and ensure that it's properly supported (either on your knee, or using a large cable tie to suspend from the coil spring).
Disconnect the Pad Wear Sensor
Now we need to disconnect the brake pad wear sensor. To do so, trace back from the sensor to the connector (should be on a bracket just behind the caliper).
To remove the connector from it's mount, use the flathead screwdriver to lift the plastic catch slightly, then turn the entire connector block 90 degrees.
Use the flat head to push the release in on the connector, and gently work free. It's not the end of the world if you damage the connector on the side nearest the pads, but breaking the side nearest the car is a costly mistake!
You should now be able to remove the old pads.
Step 3 - Clean the Area and Check the Equipment
A brake pad change is a good opportunity to get rid of some of the residual brake dust that builds up. With the old pads removed, give the entire area a good spray of brake dust arrestor and leave to dry for a few minutes.
Check that the brake rotors are in good condition - no warping or dents. They're vented disks so expect to see some rust, but there should be a reasonable amount of metal surrounding the vents....
Step 4 - Make Space
We need to push the brake piston back into the calliper so that there'll be room for the new pads.
Using the G-Clamp (or a brake rewinder if you have one), gently push the piston back as far as it will go.
Step 5 - Insert the New Pads
The best way to insert the new pads is to leave the sensor unconnected until the end.
Insert the outside brake pad first, it should simply slot into the calliper mounting bracket. Carefully grease the back of it (the side nearest you, not the friction material) using copper grease.
Carefully wipe copper grease down the backside of the other pad (the side with the clip, not the friction material). Make sure you keep your hands clean of grease as we don't want them on the brakes themselves.
Insert the pad into the calliper, pushing on both wings should be sufficient to pop the clip into the piston. Carefully route the sensor wire as you bring the calliper into place (ensuring that both pads sit within it.
Slightly tighten each of the slide bolts until you're sure they're biting, and then tighten both evenly, as tight as you can manage by hand.
Step 6 - Re-Connect the Sensor Wire
Route the sensor cable back up to the connector and connect it up.
Carefully place the connector back into the mount by inserting sideways and then rotating 90 degrees.
Step 7 - Re-fit the Wheel
The final step is to refit the wheel, which thanks to the aforemention loose rotor isn't always as straight forward as it should be.
Remove the retaining bolt that we screwed in after removing the wheel, and replace it with your biro/pencil.
Using the Biro/Pencil to help you line the wheel up, offer the wheel up to the hub. As soon as the holes are aligned, evenly tighten the wheel retaining bolts into place.
Get the car back on the ground, and then torque the nuts to at least 50Nm, but no more than 60.
Step 8 - Rinse and Repeat
Repeat the process on the other side of the car now. Remember that you'll need to pump your brake pedal a few times before it'll work.