Brake Rotor Thickness, Checking, With Stamped Minimum Weight

Special tools and workshop equipment required 

• Commercially available digital caliper or micrometer gauge.

Here the minimum weight "min.weight" is stamped on the brake rotor on the brake rotor cup the tolerance for the brake rotor thickness is still only +0.05 mm.

Procedure 

Fig 1: Identifying Ceramic Brake Rotor Data

Courtesy of AUDI OF AMERICA, LLC

The minimum permitted brake rotor thickness "min.th." is engraved in the brake rotor cup -3-.

-- Measure the brake rotor thickness -x- three times around the circumference in addition to the individual wear indicators.

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

Courtesy of AUDI OF AMERICA, LLC

• Here the tolerance is much smaller than on traditional measurement.
• When dimension x = min.th. additional tolerance of +0.05 mm is reached, then also determine the brake rotor wear at the wear indicators.

If the permissible minimum thickness "min.th." is reached or is under, then the brake rotor can no longer be used. The brake rotor must be replaced.

If there is abrasion both brake rotors on both sides of the axle must always be replaced.

The brake pads must always be replaced.