Wear Assessment By Checking Thickness Of Brake Disc; Wear Assessment According To Wear Indicators - Audi A8 2003 Workshop Manual

If one of the three wear limits defined below has been reached,
do NOT continue using the brake disc. 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.
3.1 Wear assessment by checking thick‐
ness of brake disc
Special tools and workshop equipment required
♦ Use a commercially available caliper gauge or micrometer
gauge.
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The minimum permissible thickness of the brake disc is engraved
with respect to the correctness of information in this document. Copyright by AUDI AG.
as "min.Th." on the brake disc hub.
– Measure the brake disc thickness at three points round the
outside of the disc next to the individual wear indicators -x-.
Note
If the thickness is x = min. Th. + 0.2 mm, additionally check the
wear of the brake disc by inspecting the wear indicators
⇒ page 11 .
When minimum weight is stamped on hub of brake disc:
Note
When minimum weight is stamped on hub of brake disc:
♦
If the thickness is x = min. Th. + 0.05 mm, additionally check
♦
the wear of the brake disc by inspecting the wear indicators
⇒ page 11 .
All types of ceramic brake discs (continued):
If the thickness of the brake disc is less than or equal to the min‐
imum permissible thickness "min.Th.", do NOT continue using the
brake disc. 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.
3.2 Wear assessment according to wear in‐
dicators
Wear indicators are positioned at intervals of 120 degrees on the
friction surface of the brake disc.
Audi A8 2003 ➤
Brake system - Edition 03.2013
3. Assessing degree of wear on ceramic brake discs
11