Measuring brake lining thickness (Audi A4 B6)

The linings on the front disc brakes are subject to greater loads than the linings on the rear wheels, therefore they wear out faster. Check the thickness of the linings regularly, this should be done at least every 15 thousand km. If the thickness of the brake linings is 7 mm (including back plate), this means that the linings have reached the wear limit and need to be replaced. On one bridge, all linings must be replaced at once.





1. The outer brake pads can be inspected without removing the wheel. To do this, you need a flashlight, the pads are visible through the hole. The inner pad can only be seen with a mirror. If in doubt, remove the wheel to make it easier to access the pad.



2. A coin is suitable as a measure. Hold it between the brake disc and the brake pad. If the thickness of the pad is equal to the thickness of the coin, it is time to change it.

Brake pedal and brake pad

The free travel of the brake pedal should be no more than a third of the total travel. If the pedal can be pressed lower (check with your hand), check your brake discs immediately - they may be very worn or stuck. The brake caliper may be rusty.

However, checking the brake pedal does not replace checking the brake pads: when braking, the brake cylinder piston moves the worn pad so that after releasing the pedal, it always occupies the same basic position relative to the brake disc. Thus, the pedal stroke remains almost the same until the pads wear down to their minimum thickness. If the pedal stroke decreases when "rocking", air may have entered the system. In this case, it is necessary to remove the air and find the cause.