Ceramic Brake Rotors, Determining Wear

WARNING: This page is about a different variant/trim than selected.

NOTE:

Ceramic brakes are installed only in the front.

Checking Threaded Connectors on the Brake Rotor Ring and Brake Rotor Cup

WARNING:

The brake rotor ring and the brake rotor cup are attached to each other and must never be separated. Never loosen the threaded connector on the brake rotor cup.

Ceramic Brake Rotor Identification on the Brake Rotor Cup

Fig 1: Identifying Ceramic Brake Disc, Determining Wear

Courtesy of AUDI OF AMERICA, LLC

Running Direction
Supplier
On-Going Brake Rotor Production Number
Audi Part Number
NOTE:
The Audi part number on the brake rotor is an example and will be different on each vehicle model.
Brake Rotor Date of Manufacture
Brake Rotor Minimum Permissible Thickness
NOTE:
The minimum permissible brake rotor thickness is different for each vehicle model.
New Brake Rotor and Cup Weight
Checking Threaded Connectors on the Brake Rotor Ring and Brake Rotor Cup

WARNING:
The brake rotor ring and the brake rotor cup are attached to each other and must never be separated. Never loosen the threaded connector on the brake rotor cup.

NOTE:
The weight of a new brake rotor and cup will be different on each vehicle model.

Clean the Brake Rotor Before Measuring the Wear.

WARNING:

Never clean the brake rotor with water or any other fluid. This will make the measuring result incorrect.

CAUTION:

Wear breathing protection if using compressed air to clean brake rotors and the brake system.

NOTE:

The brake rotor vent holes must be free of brake dust and dirt. It may be necessary to use something suitable to clean the holes. Use not use force.

Clean the brake rotor thoroughly with compressed air between the cooling channels and the vent holes.

CAUTION:

Wear breathing protection if using compressed air to clean brake rotors and the brake system.

Determining Brake Rotor Wear:

1. Check the brake rotor thickness.
2. Check the wear indicators.

1. Check the brake rotor thickness
If the brake rotor thickness is within the permissible range → then the brake rotor is OK
the thickness of the brake rotor is in the critical range: minimum + 0.2 mm		when reaching or not reaching the limit
↓↓		↓↓
Wear indicators		Brake Rotor, Replacing
↓↓		----------
3. Using the wear indicators to check the brake rotor wear
If none of the six wear indicators are burned out → then the brake rotor is OK.
----------		One of the six wear indicators is completely burned out
---------		↓↓
----------		Brake Rotor, Replacing

Always Replace the Brake Rotors on Both Sides of the Axle When

The brake rotors must replaced because they are worn.
the replacement brake rotor has been technically modified, which can be determined by the revised part number.

NOTE:

If one of the three defined wear limit is reached, then the brake rotor can no longer be used. Replace the brake rotor.

In this case, replace the brake rotors on each side of the axle.

Brake pads likewise must always be replaced on both sides of the axle.

Check the Brake Rotor Thickness

Special tools and workshop equipment required

Use a commercially available caliper gauge or a micrometer gauge

The permissible minimum brake rotor thickness "min. Th." is engraved in the brake rotor cup.

-- Measure the brake rotor thickness three times on each wear indicator the circumference of the of the brake rotor -x-.

Fig 2: Measuring Brake Disc Thickness Three Times On Each Wear Indicator Circumference Of Brake Disc

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Check the brake rotor wear also using the wear indicators after determining dimension x = min. Th. +0.2 mm.

The brake rotor may no longer be driven once the permissible minimum thickness "min.Th." has been reached. Replace the brake rotor.

NOTE:

Brake pads likewise must always be replaced on both sides of the axle.

In this case, replace the brake rotors on each side of the axle.

Check the Wear Indicators

The wear indicators on the brake rotor friction surfaces are spaced 120 degrees apart from each other.

The wear indicators -arrow- have a different color to make it easier to recognize them.

Fig 3: Identifying Wear Indicator By Difference In Color To Rotor Surface Metal

Courtesy of AUDI OF AMERICA, LLC

NOTE:

There are three indicators on the front and back of the brake rotor for determining wear on a ceramic brake rotor.

The following illustration shows a wear indicator that is OK.

Fig 4: Identifying OK Wear Indicator

Courtesy of AUDI OF AMERICA, LLC

NOTE:

The indicator will look like a dark, burned-out indentation when there is wear on the ceramic brake rotor.

If one of the six indicators is completed burned out, then the brake rotor can no longer be driven. Replace the brake rotor.

The following two illustrations show burned out wear indicators. In this case the brake rotor must be replaced.

Fig 5: Identifying Burned Out Wear Indicator

Courtesy of AUDI OF AMERICA, LLC

NOTE:

In this case, replace the brake rotors on each side of the axle.

Fig 6: Identifying Burned Out Wear Indicator

Courtesy of AUDI OF AMERICA, LLC

NOTE:

Brake pads likewise must always be replaced on both sides of the axle.

Checking Threaded Connectors On The Brake Rotor Ring And Brake Rotor Cup

WARNING:

The brake rotor ring and the brake rotor cup are attached to each other and must never be separated. Never loosen the threaded connector on the brake rotor cup.