Ceramic Brake Rotor, Determining Wear

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NOTE:

Ceramic brakes only installed 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.

Identification on the ceramic brake rotor 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
Minimum Permissible Thickness
NOTE:
The minimum permissible brake rotor thickness is different for each vehicle model.
New Ceramic Brake Rotor and Cup Weight
NOTE:
Depending on the version, the minimum weight of the driven brake rotor is stamped on the brake rotor cup. If the stamped minimum weight is reached or falls below, then the brake rotor must be replaced. Always replace brake rotors on both sides of the axle.

CAUTION:
If the minimum weight of the brake rotor "min. weight" is displayed on the brake rotor cup, then the brake rotor must be weighed to determine additional wear.

CAUTION:
Only brake rotors of the same version may be installed on an 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.

Clean the brake rotor before determining the wear.

WARNING:

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

CAUTION:

Always wear a mouth and nose mask when using compressed air to clean the brake rotor 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. Do not use force.

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

CAUTION:

Always wear a mouth and nose mask when using compressed air to clean the brake rotor and the brake system.

Determining brake rotor wear:

1. Checking the brake rotor thickness to determine the wear
2. Using the wear indicators to determine the wear

1. Checking the brake rotor thickness to determine the wear. Refer to BRAKE ROTOR THICKNESS, CHECKING WITHOUT STAMPED 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 Th + 0.2 mm		when reaching or not reaching the limit
↓↓		↓↓
Wear indicators		Replace brake rotor
↓↓		----------
2. Using the wear indicators to determine brake rotor wear. Refer to WEAR INDICATORS, CHECKING .
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
---------		↓↓
----------		Replace brake rotor

NOTE:

Depending on the version, the minimum weight of the driven brake rotor is stamped on the brake rotor cup. If the stamped minimum weight is reached or falls below, then the brake rotor must be replaced. Always replace brake rotors on both sides of the axle.

Proceed as follows.

CAUTION:

If the minimum weight of the brake rotor "min. weight" is displayed on the brake rotor cup, then the brake rotor must be weighed to determine additional wear. If the minimum weight is reached or falls below, then the brake rotor must be replaced.

Replace brake rotors on each axle.

Brake rotor with stamped minimum weight.

1. Checking the brake rotor thickness to determine the wear
2. Using the wear indicators to determine the wear
3. Checking the weight to determine wear

1. Checking for wear by testing the brake rotor thickness with reference to the stamped-on minimum weight. Refer to BRAKE ROTOR THICKNESS, CHECKING WITH STAMPED 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 Th + 0.05 mm		when reaching or not reaching the limit
↓↓		↓↓
Wear indicators		Replace brake rotor
↓↓		----------
2. Using the wear indicators to determine brake rotor wear. Refer to WEAR INDICATORS, CHECKING .
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
		↓↓
		3. Weighing the brake rotor. Refer to BRAKE ROTOR, WEIGHING .
		If the minimum weight is not reached, the rotor is OK.
		If the minimum weight is reached
---------		↓↓
----------		Replace brake rotor

Always replace the brake rotors on both sides of the axle when:

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

If one of the three defined wear limits is reached, then the brake rotor can no longer be used. The brake rotor must be replaced.

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.