Volkswagen ID.4 2021 Instruction manual

Workshop Manual
ID.4 2021 ➤
Brake system
Edition 07.2021
Service
Service Department. Technical Information

List of Workshop Manual Repair Groups
Repair Group
00 - Technical data
45 - Anti-lock brake system
46 - Brakes - mechanism
47 - Brakes - hydraulics
Technical information should always be available to the foremen and mechanics, because their
careful and constant adherence to the instructions is essential to ensure vehicle road-worthiness
and safety. In addition, the normal basic safety precautions for working on motor vehicles must, as
a matter of course, be observed.
Service

Contents
00 - Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 Safety information and repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Allocation of PR number - brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3 Technical data for brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1 Brake master cylinder and brake servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 Front brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.3 Rear brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4 Brake test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1 Vehicle checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2 Checking electromechanical parking brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
45 - Anti-lock brake system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1 Safety information and repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.2 Repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Overview of fitting locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1 Overview of fitting locations – ABS/ESP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Control unit and hydraulic unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 Assembly overview – control unit and hydraulic unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55] . . . . . . . . . . . . 14
3.3 Connecting brake lines to hydraulic unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
4 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.1 Assembly overview – speed sensors on front axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.2 Assembly overview – speed sensors on rear axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.3 Removing and installing speed sensor on front axle [G45]/[G47] . . . . . . . . . . . . . . . . . . . . 28
4.4 Removing and installing speed sensor on rear axle [G44]/[G46] . . . . . . . . . . . . . . . . . . . . 29
4.5 Checking ABS sensor ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
46 - Brakes - mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1 Safety information and repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
1.2 Repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
2 Front brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.1 Assembly overview – front brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.2 Removing and installing brake pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
2.3 Removing and installing brake caliper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
3 Rear brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.1 Assembly overview – rear brake, drum brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.2 Assembly overview – brake shoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
3.3 Removing and installing brake shoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4 Parking brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.1 Assembly overview – parking brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.2 Removing and installing control unit for electromechanical parking brake [J540] . . . . . . . . 55
4.3 Removing and installing parking brake motor [V282]/[V283] . . . . . . . . . . . . . . . . . . . . . . 56
5 Brake pedal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.1 Assembly overview – brake pedal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
5.2 Separating brake pedal from brake servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
5.3 Connecting brake pedal to brake servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
ID.4 2021 ➤
Brake system - Edition 07.2021
Contents i

5.4 Removing and installing brake pedal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.5 Removing and installing mounting bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
47 - Brakes - hydraulics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
1 Safety information and repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
1.1 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
1.2 Repair notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2 Brake servo and brake master cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
2.1 Assembly overview – brake servo/brake master cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . 68
2.2 Removing and installing brake servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3 Hydraulic system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.1 General notes on brake fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.2 Bleeding hydraulic system following standard procedure . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.3 Subsequent bleeding of hydraulic system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
3.4 Testing for leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.5 Checking wheel brake cylinder for leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
ID.4 2021 ➤
Brake system - Edition 07.2021
ii Contents

00 – Technical data
1 Safety information and repair notes
1000579J4169.001.1 - 07.2021
1.1 Safety information
⇒ Safety information and repair notes; Rep. gr. 00; Safety infor‐
mation
1.2 Repair notes
⇒ Safety information and repair notes; Rep. gr. 00; Repair notes
ID.4 2021 ➤
Brake system - Edition 07.2021
1. Safety information and repair notes 1

2 Identification
2.1 Allocation of PR number - brakes
2.1.1 Front brakes
Relevant information on the installed brakes can be found in the
vehicle-specific notes in ElsaPro/erWin.
♦ For allocation, refer to ⇒ Electronic parts catalogue (ETKA) .
♦ The following table explains the PR numbers. This data is
important for the brake caliper/brake disc and brake pads.
Drive PR No. Front brake
Rear-wheel drive 1LB / 1LF 18”, 1K, 60 in diam.
Rear-wheel drive
and all-wheel drive 1LC / 1LN 18”, 1K, 46/46 in di‐ am.
2.1.2 Rear brakes
Relevant information on the installed brakes can be found in the
vehicle-specific notes in ElsaPro/erWin.
♦ For allocation, refer to ⇒ Electronic parts catalogue (ETKA) .
♦ The following table explains the PR numbers. This informa‐
tion is important for the wheel brake cylinder/brake drum and
brake shoe combination.
Drive PR No. Rear brake
Rear-wheel drive
and all-wheel drive 1KB 11” drum brake
ID.4 2021 ➤
Brake system - Edition 07.2021
2 Rep. gr.00 - Technical data
Volkswagen Technical Site: https://vwts.ru

3 Technical data for brakes
3.1 Brake master cylinder and brake servo
Brake master cylinder Diameter in mm 25.4
Brake servo Electromechanical brake servo
3.2 Front brakes
Front brake, 18”, 1K, 60 in diam.
Item PR No. 1LB, 1LF
1 Brake caliper 18”, 1K, 60 in diam.
2 Brake pad,
thickness mm 11
Brake pad,
wear limit with‐
out backplate
mm 2
3 Brake carrier
4 Wheel bearing
housing with
wheel bearing
5 Brake disc Diam‐
eter in
mm
330
Brake disc,
thickness mm 23
Brake disc,
wear limit mm 20
6 Brake caliper
piston Diam‐ eter in
mm
60
Front brake, 18”, 1K, 46/46 in diam.
ID.4 2021 ➤
Brake system - Edition 07.2021
3. Technical data for brakes 3

Item PR No. 1LC, 1LN
1 Brake caliper 18”, 1K, 46/46 in diam.
2 Brake pad,
thickness mm 11
Brake pad,
wear limit with‐
out backplate
mm 2
3 Brake carrier
4 Wheel bearing
housing with
wheel bearing
5 Brake disc Diam‐
eter in
mm
358
Brake disc,
thickness mm 30
Brake disc,
wear limit mm 27
6 Brake caliper
piston Diam‐ eter in
mm
60
3.3 Rear brakes
Drum brakes
ID.4 2021 ➤
Brake system - Edition 07.2021
4 Rep. gr.00 - Technical data

Item PR No. 1KA
1 Wheel brake
cylinder mm 23.8
2 Brake lining,
width mm 52
Brake lining,
thickness mm 4.55
Brake lining,
minimal thick‐
ness
mm 1.0
3 Brake drum Diam‐
eter in
mm
279.8
Brake drum,
wear limit Diam‐ eter in
mm
280.8
ID.4 2021 ➤
Brake system - Edition 07.2021
3. Technical data for brakes 5

4 Brake test
4.1 Vehicle checks
Carry out the brake test on a single-axle roller dynamometer.
The maximum test speed must not exceed 6 km/h.
The test rigs authorised by Volkswagen fulfil these require‐
ments.
4.2 Checking electromechanical parking
brake
Activate “TÜV mode”:
Important
• No faults influencing function of roller dynamometer (e.g.
rotational speed sender fault) detected
• Seat belt is fitted
• Rear axle on single-axle roller dynamometer
• No gear engaged
• Vehicle’s drive system deactivated (at least 3 seconds)
• Front wheels must be stationary (at least 3 seconds)
• Rear wheels must rotate for at least 3 seconds at a constant
speed between 2 km/h and 9 km/h.
When entering “TÜV mode”, the yellow electric parking brake
and handbrake fault warning lamp -K214- will light up.
In “TÜV mode”, the electromechanical parking brake does not
close fully when the button is first pressed.
The tension is increased gradually by actuating the electrome‐
chanical parking brake button -E538- 2 times in succession.
♦ Initial actuation: both sides of parking brake are actuated to
the point of application
♦ Second actuation: both sides of parking brake are fully ap‐
plied
End “TÜV mode”:
As soon as one of the preconditions for the TÜV mode is no
longer fulfilled, the TÜV mode is immediately terminated, for
example:
Important
• Front wheels, speed over 0 km/h
• Rear wheels, speed under 2.5 km/h or over 9 km/h
ID.4 2021 ➤
Brake system - Edition 07.2021
6 Rep. gr.00 - Technical data

45 – Anti-lock brake system
1 Safety information and repair notes
1.1 Safety information
⇒ Safety information and repair notes; Rep. gr. 00; Safety infor‐
mation
1.2 Repair notes
⇒ Safety information and repair notes; Rep. gr. 00; Repair notes
ID.4 2021 ➤
Brake system - Edition 07.2021
1. Safety information and repair notes 7

2 Overview of fitting locations
2.1 Overview of fitting locations – ABS/ESP
The overview shows a left-hand drive vehicle as an example.
ID.4 2021 ➤
Brake system - Edition 07.2021
8 Rep. gr.45 - Anti-lock brake system

1 - ABS control unit -J104- /
ABS hydraulic unit -N55-
❑ Fitting location for right-
hand drive vehicles: in
vehicle front end on
front passenger side
❑ ⇒ Rep. gr. 45; Assem‐
bly overview – control
unit and hydraulic unit
❑ ⇒ Rep. gr. 45; Remov‐
ing and installing ABS
control unit [J104]/ABS
hydraulic unit [N55]
2 - Diagnostic connection
3 - Control unit with display
unit for driver information sys‐
tem -J1254-
❑ With brake pad warning
lamp -K32-
❑ With ABS warning lamp
-K47-
❑ With TCS and ESP but‐
ton -K155-
❑ With brake system
warning lamp -K118-
❑ ⇒ Electrical system;
Rep. gr. 90; Dash pan‐
el insert; Removing and
installing control unit
with display unit for
driver information sys‐
tem [J1254]
4 - Display unit for front infor‐
mation display and operating
unit control unit -J685-
❑ With button for TCS
and electronic stabilisation program -E256- , activation via menu in Infotainment system
❑ ⇒ Communication; Rep. gr. 91; Infotainment system; Removing and installing control unit for front
display and information control panel
5 - Rear right speed sensor -G44- / rear left speed sensor -G46-
❑ ⇒ Rep. gr. 45; Assembly overview – speed sensors on rear axle
❑ ⇒ Rep. gr. 45; Removing and installing speed sensor on rear axle [G44]/[G46]
6 - Front right speed sensor -G45- / front left speed sensor -G47-
❑ ⇒ Rep. gr. 45; Assembly overview – speed sensors on front axle
❑ ⇒ Rep. gr. 45; Removing and installing speed sensor on front axle [G45]/[G47]
7 - Steering angle sensor -G85- in steering rack
❑ Cannot be renewed individually
❑ ⇒ Running gear, axles, steering; Rep. gr. 48; Steering rack; Removing and installing steering rack
8 - Brake servo
❑ ⇒ Rep. gr. 47; Assembly overview – brake servo/brake master cylinder
❑ ⇒ Rep. gr. 47; Removing and installing brake servo
ID.4 2021 ➤
Brake system - Edition 07.2021
2. Overview of fitting locations 9

3 Control unit and hydraulic unit
3.1 Assembly overview – control unit and
hydraulic unit
3.1.1 Assembly overview – control unit and hydraulic unit, left-hand drive vehi‐
cles
ID.4 2021 ➤
Brake system - Edition 07.2021
10 Rep. gr.45 - Anti-lock brake system

1 - ABS control unit -J104-
❑ ⇒ Rep. gr. 45; Remov‐
ing and installing ABS
control unit [J104]/ABS
hydraulic unit [N55]
2 - Brake line to rear right
wheel brake cylinder
❑ 5.25 mm in diameter
and union screw with
short M12 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools
VAS 6854, VAG 1410/7
and VAG 1410/6:
12 Nm
3 - Brake line to front left
brake caliper
❑ 5.25 mm in diameter
and union screw with
M10 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools
VAS 6854, VAG 1410/7
and VAG 1410/6:
12 Nm
4 - Brake line to front right
brake caliper
❑ 5.25 mm in diameter
and union screw with
short M12 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
5 - Brake line to rear left wheel brake cylinder
❑ 5.25 mm in diameter and union screw with M10 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
6 - ABS hydraulic unit -N55-
❑ ⇒ Rep. gr. 45; Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55]
7 - Torx bolt
❑ Qty. 4
❑ Renew after removing
❑ 1st stage: 1.25 Nm (to allow seal to settle)
❑ 2nd stage: 2.5 Nm
8 - Brake line to secondary piston circuit of brake master cylinder
❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
9 - Brake line to primary piston circuit of brake master cylinder
ID.4 2021 ➤
Brake system - Edition 07.2021
3. Control unit and hydraulic unit 11

❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
10 - Rubber mounting
11 - Bracket
12 - Brake servo -NX6-
❑ Checking: ⇒ Vehicle diagnostic tester
❑ ⇒ Rep. gr. 47; Assembly overview – brake servo/brake master cylinder
❑ ⇒ Rep. gr. 47; Removing and installing brake servo
13 - Bolt
❑ Qty. 3
❑ 20 Nm
14 - Bracket
15 - Bolt
❑ Qty. 2
❑ 8 Nm
3.1.2 Assembly overview – control unit and hydraulic unit, right-hand drive
ID.4 2021 ➤
Brake system - Edition 07.2021
12 Rep. gr.45 - Anti-lock brake system

1 - Brake line to rear right
wheel brake cylinder
❑ 5.25 mm in diameter
and union screw with
short M12 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools
VAS 6854, VAG 1410/7
and VAG 1410/6:
12 Nm
2 - Brake line to front left
brake caliper
❑ 5.25 mm in diameter
and union screw with
M10 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools
VAS 6854, VAG 1410/7
and VAG 1410/6:
12 Nm
3 - Brake line to front right
brake caliper
❑ 5.25 mm in diameter
and union screw with
short M12 × 1 thread
❑ mit handelsüblichem
Standardwerkzeug:
14 Nm
❑ With special tools
VAS 6854, VAG 1410/7
and VAG 1410/6:
12 Nm
4 - Brake line to rear left wheel brake cylinder
❑ 5.25 mm in diameter and union screw with M10 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
5 - Brake line to secondary piston circuit of brake master cylinder
❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
6 - Brake line to primary piston circuit of brake master cylinder
❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
7 - Bracket
8 - Bolt
❑ Qty. 2
❑ 20 Nm
9 - Bolt
❑ 20 Nm
ID.4 2021 ➤
Brake system - Edition 07.2021
3. Control unit and hydraulic unit 13

10 - Rubber mounting
11 - Bracket
12 - Bolt
❑ 8 Nm
13 - ABS control unit -J104- with ABS hydraulic unit -N55-
❑ ⇒ Rep. gr. 45; Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55]
14 - Brake line from secondary piston circuit to hydraulic unit
❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
15 - Brake line from primary piston circuit to hydraulic unit
❑ 6 mm in diameter and union screw with M12 × 1 thread
❑ mit handelsüblichem Standardwerkzeug: 14 Nm
❑ With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm
16 - Brake servo -NX6-
❑ Checking: ⇒ Vehicle diagnostic tester
❑ ⇒ Rep. gr. 47; Assembly overview – brake servo/brake master cylinder
❑ ⇒ Rep. gr. 47; Removing and installing brake servo
3.2 Removing and installing ABS control
unit [J104]/ABS hydraulic unit [N55]
3.2.1 Removing and installing ABS control
unit [J104]/ABS hydraulic unit [N55],
left-hand drive vehicles
Special tools and workshop equipment required
♦ 11 mm open ring spanner insert -V.A.G 1410/6-
♦ Torque wrench -VAS 6854-
♦ Universal joint -V.A.G 1410/7-
♦ assembly tool -V.A.G 1410/8-
♦ brake pedal actuator -V.A.G 1869/2-
♦ engine bung set -VAS 6122-
For sealing plugs (assembly parts), see electronic parts cata‐
logue (ETKA)
ID.4 2021 ➤
Brake system - Edition 07.2021
14 Rep. gr.45 - Anti-lock brake system

1 - M10 sealing plugs
2 - M12 sealing plugs
Removing
The ABS control unit -J104- -1- will henceforth be referred to as
“control unit”.
The ABS hydraulic unit -N55- -2- will henceforth be referred to
as “hydraulic unit”.
– If the control unit is renewed, carry out the test plan for the
renewal of the control unit using ⇒ Vehicle diagnostic tester .
– Disconnect battery ⇒ Electrical system; Rep. gr. 27; Battery;
Disconnecting and connecting battery .
– Remove air intake unit of heater and air conditioning unit
⇒ Heating, air conditioning system; Rep. gr. 87; Front heater
and air conditioning unit; Removing and installing air intake
unit of heater and air conditioning unit .
– Press down locking slide in direction of -arrow A- .
– Release electrical connector -1- in direction of -arrow B- .
– Disconnect electrical connector -1- .
– Fit brake pedal actuator -V.A.G 1869/2- .
ID.4 2021 ➤
Brake system - Edition 07.2021
3. Control unit and hydraulic unit 15

– Connect bleeder hose of bleeder bottle to bleeder screw of
front left brake caliper -1- .
– Open bleeder screw.
– Connect bleeder hose of second bleeder bottle to bleeder
screw of rear left wheel brake cylinder -1- .
– Open bleeder screw.
– Depress brake pedal at least 60 mm using brake pedal ac‐
tuator -V.A.G 1869/2- .
– Close front left and rear left bleeder screws.
– Do not remove brake pedal actuator -V.A.G 1869/2- .
NOTICE
Risk of damage to brake lines when bending.
– Never excessively bend the brake lines in the area of the
hydraulic unit.
– Unclip brake lines from plenum chamber bulkhead.
ID.4 2021 ➤
Brake system - Edition 07.2021
16 Rep. gr.45 - Anti-lock brake system