General, Technical Data - Brake System (Cabriolet): Other Audi S5 I facelift

CERAMIC BRAKE ROTORS, EVALUATING

Note. Ceramic brakes are installed only in the front.

Scheme 40

1. Cooling Channels
2. Friction Surface
3. Base Material

Ceramic Brake Rotor Visual Characteristics

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

The friction surface on a new brake rotor already has stress cracks made during the production process. These stress cracks are all different.

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Note. Stress cracks do not mean the ceramic brake rotor is faulty.

The stress cracks are somewhat visible and can be different from each other in strength.

Surface Cracks in Cooling Duct Crosspieces

The cracks on the surface of the cooling channels -arrow- were produced during the manufacturing process.

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Note. Surface cracks in the cooling duct cross pieces do not mean the ceramic brake rotor is faulty.

Cracks in Ceramic Brake Rotor Connection Area

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

If the ceramic brake rotors have cracks near the threaded connectors on the cup leading to the friction surface on the brake rotor -arrows-, then the brake rotors must be replaced.

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Crack in the threaded connection area not permitted.

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Replace the Brake Rotors on Both Sides of the Axle When

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

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

Chamfer

Chips on the edge -arrow- of the brake rotor are caused by mechanical damage.

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The following are permitted

1. Maximum width / depth 2 mm.
2. maximum length = 10 mm
3. Maximum number of chips on the brake rotor = 3

If any of these criteria are exceeded, replace the brake rotor.

Replace the Brake Rotors on Both Sides of the Axle When

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

Note. Brake pads likewise must always be replaced on both sides of the axle. If ceramic brake disc starts to show material break down on friction surface greater then ceramic brake discs must be replaced.

Nicks on Ceramic Brake Rotor

Replace the ceramic brake rotor if it has nicks on the friction surface with a surface greater than 1cm 2 -arrow-.

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Replace the Brake Rotors on Both Sides of the Axle When

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

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

Crack in Cooling Duct

If the ceramic brake rotor has a crack on the friction surface leading to or through the cooling channel -arrow-, the replace the ceramic brake rotor.

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CERAMIC BRAKE ROTORS, DETERMINING WEAR

Note. Ceramic brakes are installed only in the front.

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

Ceramic Brake Rotor Identification on the Brake Rotor Cup

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1. Running Direction
2. Supplier
3. On-Going Brake Rotor Production Number
4. Audi Part Number NOTE: The Audi part number on the brake rotor is an example and will be different on each vehicle model.
5. Brake Rotor Date of Manufacture
6. Brake Rotor Minimum Permissible Thickness NOTE: The minimum permissible brake rotor thickness is different for each vehicle model.
7. 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.

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.

Determining Brake Rotor Wear

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

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

1. The brake rotors must replaced because they are worn.
2. 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

1. 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-.

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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.

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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.

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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.

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

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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

BRAKES PR CODES

The following tables show the PR number code key. This is important in order to know the brake caliper/brake rotor and brake pad combination.

Note. Hairline cracks on brake rotor friction surfaces are often observed during brake repairs. Hairline cracks up to 10 mm long are not a technical flaw and are not cause for brake rotor replacement. Brake rotors with friction surfaces that have worn through should be replaced.

Note. Ceramic brakes are installed only in the front on this model. Hairline cracks on the friction surface on ceramic brakes occur during the manufacturing process and can be found on new brakes in different stampings. Hairline cracks on the friction surfaces are not a reason to exchange the ceramic brake rotors. Every brake rotor has a singed groove to recognize the wear limit. If the brake rotor friction surface the groove are worn down to an even level, the brake rotor wear limit has been reached.

The brake system installed in a vehicle is indicated on the vehicle data label by the relevant PR number -A and B-.

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Note. Hairline cracks on brake rotor friction surfaces are often observed during brake repairs. Hairline cracks up to 10 mm long are not a technical flaw and are not cause for brake rotor replacement. Brake rotors with brake pads that have worn through should be replaced.