ID.4 2021 ➤
Brake system - Edition 07.2021
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)
14
Rep. gr.45 - Anti-lock brake system
ID.4 2021 ➤
Brake system - Edition 07.2021
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- .
3. Control unit and hydraulic unit
15
ID.4 2021 ➤
Brake system - Edition 07.2021
– 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.
16
Rep. gr.45 - Anti-lock brake system
ID.4 2021 ➤
Brake system - Edition 07.2021
NOTICE
Risk of damage due to corrosion.
– Make sure that no brake fluid gets onto electrical contacts.
– Place sufficient lint-free cleaning cloths in area of electrical
connectors.
– First, mark the two brake lines -5- and -6- , and unscrew
them from the hydraulic unit.
– Seal threaded holes with sealing plugs.
– Mark brake lines (brake calipers/wheel brake cylinders) -1-
to -4- , unscrew them, and seal threaded holes.
– Seal brake lines with engine bung set -VAS 6122- .
Note
Fit dust caps from bleeder screws on brake lines as an alterna‐
tive.
– Pull hydraulic unit and control unit -1- together with brack‐
et -3- and rubber mountings -4- upwards in direction of
-arrow- .
Installing
Install in reverse order of removal, observing the following:
♦ The hydraulic unit is pre-filled. Do not remove sealing plugs
on the hydraulic unit until the corresponding brake line is
installed to ensure a sufficient fill level and venting.
♦ When installing the hydraulic unit, make sure that the rubber
mountings are not pressed out of the bracket.
– Use assembly tool -V.A.G 1410/8- to fit brake lines in the
sequence -1- through -6- .
3. Control unit and hydraulic unit
17
ID.4 2021 ➤
Brake system - Edition 07.2021
– Tighten break line union screws in sequence -1- through
-6- .
– Remove brake pedal actuator -V.A.G 1869/2- .
– ⇒ Rep. gr. 47; Bleed hydraulic system following standard
procedure .
– If the control unit has been renewed, conclude the test plan
for the renewal of the control unit using ⇒ Vehicle diagnostic
tester .
Tightening torques
Assembling special tools for tightening brake lines
1 - Torque wrench -VAS 6854-
2 - Universal joint -V.A.G 1410/7-
3 - 11 mm open ring spanner insert -V.A.G 1410/6-
♦ ⇒ Rep. gr. 45; Assembly overview – control unit and hydraul‐
ic unit
♦ ⇒ Rep. gr. 46; Assembly overview – front brake
♦ ⇒ Rep. gr. 46; Assembly overview – brake shoes
♦ ⇒ Electrical system; Rep. gr. 27; Battery; Assembly over‐
view – battery
3.2.2
Removing and installing ABS control
unit [J104]/ABS hydraulic unit [N55],
right-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-
18
Rep. gr.45 - Anti-lock brake system
ID.4 2021 ➤
Brake system - Edition 07.2021
♦ 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)
1 - M10 sealing plugs
2 - M12 sealing plugs
Removing
The ABS control unit -J104- will henceforth be referred to as
“control unit”.
The ABS hydraulic unit -N55- 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 .
– Remove battery tray ⇒ Electrical system; Rep. gr. 27; Bat‐
tery; Removing and installing battery tray .
– 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- .
3. Control unit and hydraulic unit
19
ID.4 2021 ➤
Brake system - Edition 07.2021
– 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.
20
Rep. gr.45 - Anti-lock brake system
ID.4 2021 ➤
Brake system - Edition 07.2021
NOTICE
Risk of damage due to corrosion.
– Make sure that no brake fluid gets onto electrical contacts.
– Place sufficient lint-free cleaning cloths in area of electrical
connectors.
– First, mark the two brake lines -5- and -6- , and unscrew
them from the hydraulic unit.
– Seal threaded holes with sealing plugs.
– Mark brake lines (brake calipers/wheel brake cylinders) -1-
to -4- , unscrew them, and seal threaded holes.
– Seal brake lines with engine bung set -VAS 6122- .
Note
Fit dust caps from bleeder screws on brake lines as an alterna‐
tive.
– Pull hydraulic unit and control unit -1- together with brack‐
et -3- and rubber mountings -4- upwards in direction of
-arrow- .
Installing
Install in reverse order of removal, observing the following:
♦ The hydraulic unit is pre-filled. Do not remove sealing plugs
on the hydraulic unit until the corresponding brake line is
installed to ensure a sufficient fill level and venting.
♦ When installing the hydraulic unit, make sure that the rubber
mountings are not pressed out of the bracket.
– Use assembly tool -V.A.G 1410/8- to fit brake lines in the
sequence -1- through -6- .
3. Control unit and hydraulic unit
21
ID.4 2021 ➤
Brake system - Edition 07.2021
– Tighten break line union screws in sequence -1- through
-6- .
– Remove brake pedal actuator -V.A.G 1869/2- .
– ⇒ Rep. gr. 47; Bleed hydraulic system following standard
procedure .
– If the control unit has been renewed, conclude the test plan
for the renewal of the control unit using ⇒ Vehicle diagnostic
tester .
Tightening torques
Assembling special tools for tightening brake lines
1 - Torque wrench -VAS 6854-
2 - Universal joint -V.A.G 1410/7-
3 - 11 mm open ring spanner insert -V.A.G 1410/6-
♦ ⇒ Rep. gr. 45; Assembly overview – control unit and hydraul‐
ic unit
♦ ⇒ Rep. gr. 46; Assembly overview – front brake
♦ ⇒ Rep. gr. 46; Assembly overview – brake shoes
♦ ⇒ Electrical system; Rep. gr. 27; Battery; Assembly over‐
view – battery
3.3
Connecting brake lines to hydraulic
unit
3.3.1
Connecting brake lines to hydraulic unit, left-hand drive vehicles
To hydraulic unit:
22
Rep. gr.45 - Anti-lock brake system
2024 VW ID.4 Owner's Manual
