Audi 80 Quiz
Brake System

Master Brake Cylinder

In this manual: Brake System
Technical Description — 39Engines — 41Exhaust System — 13Cooling System — 28Fuel tank and fuel pump — 12Air Filter and Intake Ducts — 13Mono-Motronic Injection System — 18Digifant Injection System — 19KE-III-Jetronic Injection System — 35MPI and MPFI Injection Systems — 32Clutch — 11Transmission and Driveline — 21Suspension and Steering — 33Brake System — 41Anti-lock brake system — 8Wheels and Tires — 13Body Electrical System — 35Ignition System — 24Lighting — 14Signaling Devices — 7Instruments and Auxiliary Equipment — 54Heating and Ventilation — 7Body Components — 18Troubleshooting — 6Specifications — 13
~1min read

The master brake cylinder is the "control center" of the brake system. It is located at the rear left of the engine compartment and sends the "command" to apply the brakes to the brake calipers or wheel brake cylinders. For a more detailed description of its design and operation, refer to the beginning of this chapter.


Removal of Master Brake Cylinder
PROCEDURE

Drain the brake fluid from the expansion reservoir.

Remove the reservoir from the master brake cylinder.

Disconnect all brake lines from the master brake cylinder.

Unscrew both mounting bolts of the lower master brake cylinder mounting.

During installation, install a new O-ring between the brake booster and the master brake cylinder.

Tighten the mounting nut to 25 N•m.

Before installing the reservoir, lubricate the inside of the sealing plug of the reservoir connection fitting with brake fluid.

Bleed air from the brake system.

Test yourself

A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.