Brake master cylinder
Turns pedal input into hydraulic pressure.
At the brake booster or integrated brake-control assembly.
Pistons pressurize separate hydraulic circuits as pedal force is applied.
The hand pump driving a sealed fluid system.
A sinking pedal or pressure loss can have several hydraulic causes and requires inspection.
Pads and discs are measured wear items. Driving, environment and regenerative braking change wear; use the actual inspection limits.
Ordinary friction service differs greatly from carbon-ceramic replacement or hydraulic-controller work; obtain a vehicle-specific quote.
BMW brake-control packaging varies, especially across conventional and electrified models.
BMW models with hydraulic friction brakes; performance equipment and parking-brake design vary.