A6 front brakes R&R
It took me 4 hours to do one side and document it for you.
The other side was banged out in an hour. Cleaning every thread & surface.
I've never worked on this style of brakes. 16" wheels. (Audi lists TWO sizes of brakes)
This A6 model has several rotor sizes: GermanAutoparts.com:
A6, Quattro, Wagon, '99-01
***with 288x25mm rotors (PR code 1LB or 1LE)
*** PR code can be found on a sticker in front of the warranty
and service booklet and also on a sticker in the trunk. CHECK sticker FIRST!
17mm socket (6 point best) or the Audi wrench end to change a tire.
7mm hex/allen head socket
Brake Caliper tool or large "C" clamp.
Synthetic Caliper grease (High Temperature)
Rubber seal conditioner or Armor All. Q-tips.
Torque wrench. Service (Bentley) manual.
Here's the only place that looked like a trolley jack could work.
This MAY NOT be correct spot to lift the vehicle.
Using the lug wrench provided in the emergency kit in the Avant side panel
I took off the alloy wheel and here's the rotor assembly:
Here's a detail of the rotor edge machining:
Note the corrosion build up along the hub centric surface, clean that.
The minimum specs to turn the rotors and the PN# are stamped on these.
In the other Audi brakes I've done, the caliper floated on greased guide pins
and the carrier is held on by two allen head bolts or normal 6 point fasteners..
The carriers are removed to get the rotor off. Similar here:
Here the end cap/cover comes off the plastic "tube" hiding the guide pins.
A neat internal thing without accordion boots which can tear.
Here a 7mm hex/allen socket fits in to release the "pins".
Here's how to expect them to come apart. The "pins" really don't fall out.
Below the caliper is off the carrier
Close up detail of the guide pin end.
A few threads poke through and are exposed to corrosion.
Here's the integrated guide pin and recessed 7mm allen bolt head.
The torque for the installation of these two is _____ ft/lbs
The entire thick shaft gets greased and goes into seals inside the caliper.
I cleaned these rubber seals with Armor All to keep them pliable.
Rubber bushing view, where the guide pin floats.
Below is the caliper removed showing the internal pad IN the piston.
The wire is the brake pad wear indicator worn clean off the end.
Below the inner brake pad is removed from the extended piston.
A note here: I initially bent the wire retainer to take the caliper off,
it comes straight out pulling, off completely as probably the first step.
Winding in caliper piston:
There is a special Audi tool which is used to wind in (rear) pistons.
I left the tool at home, so I used this backup system.
A "C" clamp would have worked on the fronts.
The wire can be removed, I was able to finesse the tool past it.
As an extra step, I swabbed the rubber boot seals with "Armor All",
before winding the piston in to help combat dry rot, tear and boot failure.
New vs. Old (inboard) with the sensor wire worn clean through.
How they (outside pad) orient in the carrier bracket when new.
When worn they are recessed more towards the rotor.
Here, I chambfer the edges with a metal file.
Square edge left, filed right.
Pad wear wire (sensor) connectors
This side had the CV boot rip and smear grease all around,
hopefully yours is clean and easy to see.
New connector end for reference.
Here's a clue:
This is the bracket profile, adjacent
ABS wheel sensor wire shown with rubber grommet here
This connector profile is CRUCIAL to get them apart.
The connector is thicker when turned 90 degrees to its locking "rest" position.
The raised tab (dot) on the left goes into a slot on the metal bracket to keep the connector in place.
You will pry the long "arm" from the bracket to get the tab / "dot"
OUT of the slot in the metal bracket, then TURN the connector 90 degrees
(to thinnest width) to then slide it up and through the bracket channel and out.
The screw driver broke the end of the tab keeping the two pieces together.
1999 A6 Avant fronts: Vented: 4A0 615 301 C/D.
Box has BOTH letter endings
Nice crosshatch pattern on the machining of the rotor surface.
To remove the rotor you HAVE to take off the carrier bracket.
I found the control arm a place to rest the caliper while working on other things.
The clearance to the floor wasn't good for me to work on the carrier bolts.
So I used a mechanic trick to make a 17mm box end wrench a longer leverage arm...
The torque for the installation is _____ ft/lbs. Bolt heads differ from 5000/100/200.
Above I put the carriers back on by a thread to show a reference of them with the rotor off.
I then prepped the surfaces to be clean and mate well.
Wire brush and bristle brushed them too. Tool came from my golf bag.
Putting back together:
I used silicone High temperature brake grease on all the pad contact points.
Here's a detail of them.
NOTE: Don't try to hold in the rotor with the wheel bolts.
The hub assembly is close to the bolt hole ends and I turned
one too far into it and it deformed the bolt thread ends.
If you can use SHORTER bolts to trap the rotor do so.
Trapping and final seating is done by tightening the 5 wheels bolts.
The torque for the installation of these wheel bolts are _____ ft/lbs.
I'd strongly recommend using a "star" pattern in tightening each bolt a little bit each time.
Start on one bolt then skip the next one working around in a circle. (star)
Since there is an odd number of bolts 5, this guarantees you don't miss one.
The proper seating of the alloy rim ensures the rotor is flush
to the concentric hub provided the mating surface is clean and smooth.
This PAGE is NOT finished: May 31, 2005
Refer to the Bentley Manual for the proper torque specifications.
I had no manual so I guessed at the ballpark of the fasteners on other Audi brakes.
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