Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal...
BMW technical service bulletin B340521 for 2020-2021 BMW 840I, 2020-2021 BMW M8 and 2019-2021 BMW M850I and others.
- Bulletin number
- B340521
- Component
- Equipment adaptive/mobility
- Summary
- Diagnosis of Compound Brake System Complaints in M Vehicles: 1. Visible cracks are caused by high thermal stresses during rapid heating and cooling of the brake discs. Braking from high speed with cold brake components (less than 212 degrees F) increases the likelihood of cracks to form.
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