1997 AUDI A4 Master Cylinder 23mm Workshop Manual

47-36

Installing
When installing, note the following points:

- When installing brake master cylinder onto
brake servo, make sure push rod is correctly
located in brake master cylinder.

- Apply slight pressure to brake pedal to move
push rod toward brake master cylinder; this
makes it easier to guide brake master cylinder
onto push rod.

Bleeding clutch hydraulics

- Connect US1116 brake bleeder but do not
switch on yet.

- Open bleeder screw on clutch slave cylinder.

- Attach collector bottle hose.

- Switch on bleeder unit and allow approx. 100 cc
(6 oz.) of brake fluid to flow out of clutch slave
cylinder.

- Close bleeder screw.

Pa
ge 9 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

- Bleed brake system page 47
-23
.
Pa
ge 10 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

47-37

Brake servo for brake master cylinder
with 23.81 mm (0.937 in.) diameter
piston, removing and installing


Special tools and equipment

Repair Manual, Body-Exterior
Repair Manual, Body-Interior
Sealing plugs from repair kit, Part No. 1H0 698
311A
T10006 Brake pedal release tool

CAUTION!

Part numbers are listed here for reference
only. Always check with your Parts
department for the latest information.

Removing

- Remove driver's side storage compartment.

Repair Manual, Body
-Interior, Repair Group
68

Pa
ge 11 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

- Attach bleeder hose and bleeder bottle to left-
front brake caliper bleeder screw and open
bleeder screw.

- Operate brake pedal to pump out as much brake
fluid as possible.

- Close left-front bleeder screw.
Pa
ge 12 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

47-38

- Cover engine compartment to catch any spilled
brake fluid.

CAUTION!

Brake fluid must not be allowed to come into
contact with paintwork because of its caustic
effect.

- On vehicles with manual transmissions, disconnect clutch master
cylinder supply hose -1- and seal with plug.
- Disconnect harness connector from brake fluid level warning switch -2-.

- Disconnect brake lines -1- on brake master cylinder and seal brake
lines and threaded holes using plugs from repair kit.
-
Remove T45 Torx bolts -2- from brake servo.- Disconnect vacuum hose from brake servo.
Pa
ge 13 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

47-39


Releasing brake pedal
- Remove brake light switch.
1 -
Inserting T10006 brake pedal release tool
Insert the tool from below
2 -
Release procedures
- Tightly hold brake pedal.
- Lift catches off ball head using a slight
pull on tool (arrow -A-).
- Tension tool so catches do not re-
engage ball head.
- Pull brake pedal from ball head (arrow -
B-).
- Remove brake servo from plenum
chamber together with brake master
cylinder.
Pa
ge 14 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6

47-40

Installing
Note the following points:

- Adjust brake light switch page 46
-50
.

- Adjust vent valve for cruise control system
page 46
-54
.
Bleeding clutch hydraulics

- Connect US1116 brake bleeder but do not
switch on yet.

- Open bleeder screw on clutch slave cylinder.

- Attach collector bottle hose.

- Switch on bleeder unit and allow approx. 100 cc
(6 oz.) of brake fluid to flow out of clutch slave
cylinder.

- Close bleeder screw.

- Bleed brake system page 47
-23
.
Pa
ge 15 of 15 Brake master c
ylinder with 23.81 mm
(0.937 in.
) piston diameter and brake servo, com
ponent summar
y
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.47.6