High-Pressure Test

WARNING: This page is about a different car, the 2005 BMW 545i and 2004 BMW 545i. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Perform test on both brake circuits, front and rear.

Unscrew vent plug, connect pressure tester and vent. See Fig 1.
Load brake pedal with a force of approximately 112 lbs. (500 N), and block pedal with pedal support.
After 2 minutes, pressure must not drop by more than 8 percent.
Perform low-pressure test. See LOW-PRESSURE TEST .

Fig 1: Connecting Pressure Tester

Courtesy of BMW OF NORTH AMERICA, INC.