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The following is a basic guide towards replacing the rear brake pads on an Audi S2.
It should not be considered as a replacement for the official Audi procedure. The brake system
is a critical safety feature and therefore no work should be carried out without
proper equipment and relevant adherence to the official Audi documentation.
No responsisbilty is accepted for anyone attempting this procedure by following the steps contained in these pages. This is intended as a guide only and all usual precautions should be heeded when attempting work on a motor vehicle. I cannot be held responsible for any damage sustained as a result of using these pages.
Tools needed are as follows:
1. 17mm socket with breaker bar or wheel brace
3. Axle Stand(s)
4. 15mm open ended spanner
5. 13mm spanner
6. Piston windback tool or VAG Tool 3272
7. Rear brake pads, Part number 4D0 698 451 A
8. Optional : 8mm allen key / driver
First step is to park the car on a level surface and chock the front wheels. Ensure the handbrake is off. While working on one side, the opposite side at the rear should also be secured.
Use a wheel brace or 17mm socket with breaker bar to loosen the wheel bolts. Jack up the car and secure using axle stand(s). Remove the wheel and place to one side. Wheel shown here is a 6 spoke Avus wheel with the centre cap removed.
With the wheel off, you will be faced with a view similar to this shown here. The caliper is in two sections.
The main body contains the piston housing, while the bracket holds the pads. The two sections are held together
by floating guide pins secured by bolts (arrowed).
Use the 13mm spanner in conjunction with the open ended
15mm spanner to loosen the guide pin bolts at the top
and the bottom of the caliper. The 15mm may be a tight
fit in which case I use an AF 5/8". The guide pins are
held with locking compound so may require releasing
agent to assist removal.
With the guide pin bolts removed, the caliper
can be prised apart to reveal the pads.
The old pads are supposed to lift out by hand.
From past experience, the pads are usually held
in securely by the dust and corrosion and will
probably need tapped out with a hammer.
It is optional to remove the pad carrier but good
practice. They are secured by 8mm allen key headed
bolts. They can be difficult to remove due to dirt
buildup so it is essential to clean the inside of
the bolt head before attempting removal. They are
also secured with a relatively high torque. I personally
use an allen socket driver with breaker bar to remove
them. A shock with a hammer before removal helps to
loosen the threads.
With the carrier removed the operation of the guide
pins should be checked. They should be free to move
with no stickiness or obstruction. If necessary the guide
pins should be lubricated with special guide pin grease.
This is available with any guide pin service kit.
The rubber guide pin boots should be checked for splits
or damage and replaced as necessary. It is worthwhile to
clean or file the edges of the pad runners to ensure that
the new pads to be fitted are free to move.
Before fitting new pads, the brake piston needs to be
returned to it's original position. Open the bonnet and
remove the brake fluid reservoir cap. This makes it easier
to return the piston into the housing.
Use VAG 3272 or a similar piston windback tool to turn
the piston into the housing. Note that the piston is
threaded so no attempt should be made just to push.
The piston needs to go all the way in to allow enough
clearance for new pads.
After the pads have been replaced, the footbrake should be
pressed several times with the car on the ground to reset
the rear brakes (make sure the cap is refitted to the fluid
reservoir). Under no circumstances should the handbrake
be operated prior to this.
The following specifications apply:-
|Pad Carrier to Strut Bolts||80 Nm|
|Guide Pin Bolts (ALWAYS REPLACE)||35 Nm|
|Wheel bolts||110 Nm|