3400... Checking brake discs

Necessary preliminary tasks 

• Remove WHEELS .

Checking thickness difference:

• Measure thickness difference within brake surfaces at 8 point (spread over the circumference) with a micrometer gauge
• Compare measurement result with setpoint value. See FRONT BRAKE
  Fig 1: Measuring Brake Surface Thickness Using Micrometer

  Courtesy of BMW OF NORTH AMERICA, INC.

Check minimum brake disc thickness:

• Position special tool 34 1 280 Gauge at three measuring points in area (1) and measure.
• Compare measurement result and lowest value with setpoint value. See FRONT BRAKE
  Fig 2: Checking Minimum Brake Thickness Using Special Tool (34 1 280)

  Courtesy of BMW OF NORTH AMERICA, INC.