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Overview
The brake system of the Audi A3 ’13 is a logical progression from the brake system of its predecessor. At the start of production, 15 and 16 inch systems will be used on the front axle and a 15 inch system on the rear axle. The brake systems perform better than those of the predecessor model at comparable engine power output. Pistons with larger diameters are used on all models,
creating sportier pedal feel. The electro-mechanical parking brake (EPB) is used for the first time in this class of vehicle. The brake servo and pedal assembly are new developments. The Audi A3 ’13 is the first Audi to be equipped with Continental's ESP MK100 brake system.
ESP MK 100 by Continental (see page 15)
15 or 17 inch wheel brakes depending on engine version
Tandem master brake cylinder  with single 10“ or 11“ brake servo for left-hand drive models 7“/8“ or 8“/8“ tandem brake servo for right hand drive models
15" rear wheel brakes with electro-mechanical parking brake (EPB)
Brake system
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Engine type
R4 1.2 TFSI 77 kW R4 1.4 TFSI 90 kW R4 1.6 TDI 77 kW R4 2.0 TDI 110 kW R4 1.8 TFSI 132 kW R4 2.0 TDI 135 kW
R4 2.0 TFSI 206 kW
Minimum wheel size 15“
16“
17“
Brake type PC57-25/14 15“TRW PC57-25/14 16“TRW C60-30/13 17“TRW Number of pistons 111Piston diameter 57 mm 57 mm 60 mm Brake disc diameter
288 mm
312 mm
340 mm
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Engine type
R4 1.2 TFSI 77 kW R4 1.4 TFSI 90 kW R4 1.8 TFSI 132 kW R4 1.6 TDI 77 kW R4 2.0 TDI 110 kW R4 2.0 TDI 135 kW R4 2.0 TFSI 206 kW
Minimum wheel size 15“
17“
Brake type FNc-M38-1510 TMD Continental FNc-M42-1722 TMD Continental Number of pistons 11Piston diameter 38 mm 42 mm Brake disc diameter
272 mm
310 mm
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Brake servo, master brake cylinder, pedal assembly
10’’ or 11’’ single brake servos are used on left-hand drive models
of the Audi A3. Their size is dependent on intake manifold pres-
sure, and hence on engine type. For space reasons, a 7’’/8’’ tandem
brake servo is used on right-hand drive models. Models with the
top of the range 2.0 TFSI 206 kW engine, to be introduced at a
later date, will receive an 8’’/8’’ brake servo. The brake servo is a
new development. The brake servo is lighter than its predecessor.
This weight reduction was achieved by using high tensile steel for
the outer shells and revised contours.
Brake pressure build-up is based on a single rate characteristic.
The pedal assembly is a new development. The pedals are arranged
in suspension. A common plastic bearing pedestal is used for the
accelerator and brake pedals in order to reduce weight.
Plastic bearing pedestal
Electro-mechanical parking brake (EPB)
For the first time in this class of vehicle, the electro-mechanical
parking brake (EPB) well known from other models is used in the
Audi A3 ’13.  The system is supplied by Continental. This made it
possible to integrate the control software into the ABS control unit
J104, which likewise is sourced from Continental.
奥迪a3图片
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Design and function
Parking brake motors V282 and V283 are new developments with a modified design compared to the TRW components used previ-ously in Audi models. Gear reduction is provided by a two-step worm drive. The required self-locking effect is produced in the
second gear step. The brake caliper spindle is inserted into the spur gear of the second gear step when assembling the parking brake motor. The spindle and spur gear are connected by internal and
external torx profiles. The spindle is a component part of the ball screw and is mounted in the brake caliper. It applies pressure to the inner face of the brake piston via the spindle nut.
The spur gear driven by the electric motor transmits the rotational movement to the spindle. The thrust element moves lengthways when the spindle rotates. Depending on the direction of rotation, the thrust element moves towards the base of the brake piston or in the opposite direction. As a result, the brake piston is pressed against the brake pad (braking position) or moved away by the brake pad (release position).
The brake and release operations are controlled in the same way as in the EPB systems used in other Audi models. Deactivation of the maximum clamping force of approx. 17.5 kN is controlled by applying up to approx. 12A of electrical current. A temperature model in the control unit calculates the cooling of the brake discs and pads when the vehicle is parked and, if necessary, tightens the parking brake up to three times by briefly activating the electric motors.
Brake disc
Thrust piece (spindle nut)
Ball screw
Brake piston
Spur gear of second
gear step
Spindle
Brake piston in release position
Brake piston in braking position
Brake caliper spindle
engagement
Worm gear of second gear step Electric motor
Worm gear of first gear step