Overview - Brake Booster/Brake Master Cylinder, Electromechanical Brake Booster

Fig 1: Exploded View Of Brake Booster/Brake Master Cylinder (Electromechanical Brake Booster)

Courtesy of AUDI OF AMERICA, LLC

1. Brake Line
   • 14 Nm
   • Brake master cylinder/primary piston circuit to hydraulic unit
2. Brake Master Cylinder
   • Cannot be serviced. If malfunctioning, replace as complete unit.
   • Refer to BRAKE MASTER CYLINDER, REMOVING AND INSTALLING, ELECTROMECHANICAL BRAKE BOOSTER 
3. Brake Line
   • 14 Nm
   • Brake master cylinder/secondary piston circuit to hydraulic unit
4. Plugs
   • To install, coat with brake fluid
5. Brake Fluid Reservoir
   • Refer to BRAKE FLUID RESERVOIR, REMOVING AND INSTALLING, ELECTROMECHANICAL BRAKE BOOSTER 
6. Locking Pin
   • Slide through the brake fluid reservoir and the master brake cylinder
   • The locking pin must be pushed into the brake fluid reservoir tab.
7. Brake Fluid Level Warning Switch -F34-
   • Refer to Brake Fluid Level Warning Switch -F34-, REMOVING AND INSTALLING, ELECTROMECHANICAL BOOSTER 
8. Cap
   • With gasket
   • Seal cannot be ordered
9. Seal
   • Replace after removing.
10. Nut
    • Tightening specification and sequence. Refer to Figure.
    • Replace after removing.
    • Self-locking
11. Brake Booster Control Module -J539-
    • With integrated Brake Pedal Position Sensor -G100-
    • Refer to BRAKE BOOSTER, REMOVING AND INSTALLING, ELECTROMECHANICAL BRAKE BOOSTER 
12. O-Ring
    • Replace after removing.
13. Nut
    • 23 Nm