1999 AUDI A4 torque

45-7


ABS hydraulic unit and brake lines

The tightening torque for all brake lines on the Audi
A4 is 15 Nm (11 ft lb).
1 -
Brake master cylinder with brake servo
unit
Brake master cylinder is shown without
brake fluid reservoir
2 -
Brake line Brake master cylinder/secondary piston
circuit to hydraulic unit Bolted connection at brake master cylinder:
M12x1 Bolted connection at ABS hydraulic unit:
M12x1
3 -
Brake line Brake master cylinder/primary piston circuit
to hydraulic unit Bolted connection at brake master cylinder:
M12x1 Bolted connection at ABS hydraulic unit:
M12x1
Pa
ge 2 of 12 Anti-lock Brake S
ystem
(ABS
), Bosch 5.0
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.45.2

45-10


Removing and installing:
- Disconnect battery Ground (GND) strap.
- Seal brake lines and connections
immediately with dummy plugs.
- Bolt new hydraulic control unit to bracket,
item 13 . Remove dummy plugs from
brake line connections. Brake lines
should be connected in accordance with
designations on hydraulic control unit.
Brake line tightening torque: 15 Nm (11 ft
lb)
- Bleed brake system page 47
-23
.
- Carry out high- and low-pressure test
page 45
-5 .
- Carry out On board Diagnostic (OBD)
Repair Manual, ABS/EDL/ASR On Board
Diagnostic (OBD), Repair Group 01. 11 -
Screw
15 Nm (11 ft lb)
Pa
ge 5 of 12 Anti-lock Brake S
ystem
(ABS
), Bosch 5.0
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.45.2

45-14


EDL suction control was introduced on models with all wheel drive from
05.95. This system reduces the control noises during an EDL control
cycle.
The pressure dampers threaded into the hydraulic unit ( Fig. 2
arrows)
previously used to reduce working noises have been discontinued. The
working range of the pressure limiting valve in the hydraulic unit is raised
from 90 25 bar (1323 368 psi) to 170 25 bar (2499 368 psi).
Connector coding eliminates the risk of incorrectly connecting the
hydraulic unit. Fig. 3 Brake line connections at the hydraulic unit for ABS/EDL,
all-wheel-drive models, suction control (05.95 )
1 - Brake line tightening torque: 15 Nm (11 ft lb)
Pressure damper discontinued. The brake line is now the same
length as for FWD.
4 - Brake line tightening torque: 15 Nm (11 ft lb)
Pressure damper discontinued. The brake line is now the same
length as for FWD.
Pa
ge 9 of 12 Anti-lock Brake S
ystem
(ABS
), Bosch 5.0
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.45.2