Audi Workshop Service and Repair Manuals

Brakes The PR numbers are listed in the following tables. They indicate the required combination of brake calipers, discs and brake pads.

Brake system

Diagonally split dual-circuit braking system with ABS, EBPD, EDL, ASR, ESP, ECD and EPB

Front brakes (PR 1LT/1LA/1LJ)
Factory code (PR No.)		1LT	1LA	1LJ
Brake caliper		FN3 (16")	FBC (16")	FBC (17")
Ventilated brake disc	Ø mm	314	320	345
Brake disc, thickness	mm	25	30	30
Brake disc, wear limit	mm	23	28	28
Brake pad thickness (including backplate and damper plate)	mm	20.3	20.3	20.3
Brake pad wear limit (including backplate and damper plate)	mm	10	10	10

Front brakes (PR 1LM)
Ventilated brake disc	Ø mm	365
Brake disc, thickness	mm	34
Brake disc, wear limit	mm	32.4
Brake caliper, Brembo, 8 pistons	Ø mm	32 / 28
Brake pad thickness (including backplate and damper plate)	mm	17
Brake pad wear limit (including backplate and damper plate)	mm	9.6
Backplate	mm	5.0
Damper plate	mm	1.6

t	When performing repair work on brakes, hairline cracks are often found on the friction surface of the brake discs. Hairline cracks up to a length of 10 mm do not present a technical problem and do not justify a renewal of brake discs.

t	Brake discs with cracks going all the way across the friction surface must be renewed.

Ceramic front brakes (PR 1LW)
Brake caliper		Brembo
Ventilated brake disc	Ø mm	380
Brake disc, thickness	mm	38
Brake disc, wear limit		The minimum thickness of the brake disc is stamped onto the brake disc hub as a wear limit specification.
Brake caliper, 6 piston monoblock	Ø mm	2 x 32/ 36/ 38
Minimum pad thickness (including backplate and damper plate)	mm	9.5

Note In this model ceramic brake discs are installed on the front axle only.   Note Hairline cracks on the friction surfaces of ceramic brakes can be caused during manufacturing and therefore already appear to varying degrees when the brakes are new. Hairline cracks on the friction surfaces do not justify a renewal of the ceramic brake discs.   Note Each brake disc has a recessed groove for detecting the wear limit. When the friction surface of the brake disc is flush with the groove, the brake disc has reached the wear limit.

Rear brakes (PR 1KW/1KE)
Factory code (PR No.)		1KW	1KE
Brake caliper		CII-43 EPB (16”)	CII-43 EPB (17”)
Brake disc	Ø mm	300	330
Brake disc (not ventilated), thickness	mm	12
Brake disc (ventilated), thickness			22
Brake disc, wear limit	mm	10	20
Brake caliper, piston	Ø mm	43	43
Brake pad thickness (including backplate and damper plate)	mm	17.5	17.5
Brake pad wear limit (including backplate and damper plate)	mm	7	7

The type of brake system installed in the vehicle is indicated by the corresponding PR number -A and B- on the vehicle data sticker. t  Allocation → ETKA   Note t  When performing repair work on brakes, hairline cracks are often found on the friction surface of the brake discs. Hairline cracks up to a length of 10 mm do not present a technical problem and do not justify a renewal of brake discs. t  Brake discs and pads with cracks going all the way across the friction surface must be renewed.