Wear Assessment By Weighing Brake Disc - Audi A8 2003 Workshop Manual

Audi A8 2003 ➤
Brake system - Edition 03.2013
The wear indicators -arrow- appear in a different colour.
There are three indicators on each side of the brake disc (front
and reverse side).
The wear of the indicators is visible as a dark, burnt out recess.
Do NOT continue using the brake disc if one of the six indicators
is completely burnt out. The brake disc must be renewed.
In this case, always renew the brake discs on both sides of the
axle.
When doing so, always renew the brake pads on both sides of
the axle.
Checking area of bolted connection on friction ring and brake disc
hub:
WARNING
The brake disc ring and the brake disc hub are bolted together
and must NOT be separated. Do NOT slacken the bolted con‐
nection on the brake disc hub.
3.3 Wear assessment by weighing brake
disc
Special tools and workshop equipment required
♦ Commercially available scales with a tolerance of ± 1 g
Procedure
– Remove front brake disc for weighing.
– Remove rear brake disc for weighing.
• The brake disc must be cleaned and dry before it is weighed.
Caution
Do NOT clean the brake disc with water or other fluids as this
will falsify the results.
Note
The brake disc ventilation drillings must be completely free of
♦
dirt. Clear out carefully with a suitable tool if necessary.
Thoroughly blow out the brake discs with compressed air (in‐
♦
cluding the area between the cooling channels and ventilation
drillings).
– Carefully place the clean brake disc on the scales.
The initial weight of the brake disc with disc brake hub is engraved
on the disc brake hub.
For this model, the following maximum values are specified for
brake disc weight loss:
♦ Front brake disc: Up to 120 g weight loss from initial weight of
new brake disc.
12
Rep. gr.00 - Technical data
Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
with respect to the correctness of information in this document. Copyright by AUDI AG.