Checking the lateral runout of the brake disc | HELLA

In order to avoid the problem of brake judder when driving as early as possible, the axial runout of the new brake disc should be tested using a suitable dial gauge. The check of lateral runout is performed with the brake disc installed. The vehicle-specific specifications of the respective vehicle manufacturer are binding.

Guide value: Max. permissible lateral runout 0.07mm

The following procedure is recommended.

1. Install the brake disc on the wheel hub as prescribed with all wheel bolts or wheel nuts, and the corresponding washers and shims.
2. Fasten the dial gage with holder to the suspension strut.
3. Place the dial gage approx. 10 - 15 mm below the outer radius of the disc and align with 'zero'.
4. Turn the brake disc in the direction of travel.
5. Read off the measured values and note

Measured over several wheel revolutions, deviations should not exceed the respective tolerance values.

• This test should only be carried out on brake discs that are new or like new.
• If deviations are found, the state of the wheel hub and bearing should be considered as further fault sources.

Please always observe the specifications in the maintenance and repair notes provided by the respective vehicle manufacturer.