Audi 80 Quiz
Brake System

Checking Brake Disc Condition

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

If the wheels have been removed to check the pads, the condition of the brake discs should be checked at the same time.


PROCEDURE

There must be no deep grooves on the discs (caused by dirt or heavily worn pads). Otherwise these grooves will dig deeply into the new brake pads, significantly shortening their service life and reducing braking performance.

Discs damaged by grooves can be machined on a lathe, provided they have not become thinner than the minimum thickness through long service (see table below).

Discs that are too thin must be replaced in pairs.

A bluish tint on the brake discs is of no concern.

Brake Disc Dimensions

Brake Discs Front, non-ventilated Front, ventilated (single-piston brake caliper) Front, ventilated (two-piston brake caliper) Rear
New Disc Thickness 13 mm 22 mm 25 mm 10 mm
Minimum Thickness 11 mm 20 mm 23 mm 8 mm

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