ID.4 2021 ➤
Brake system - Edition 07.2021
14 - Sealing plug
15 - Brake fluid level warning contact -F34-
2.2
Removing and installing brake servo
2.2.1
Removing and installing brake ser‐
vo [NX6], left-hand drive vehicles
Special tools and workshop equipment required
♦ 11 mm open ring spanner insert -V.A.G 1410/6-
♦ Socket set, 39-piece -VAS 6928-
♦ Torque wrench -VAS 6854-
♦ Universal joint -V.A.G 1410/7-
♦ assembly tool -V.A.G 1410/8-
♦ brake filling and bleeding equipment -VAS 6860-
♦ engine bung set -VAS 6122-
♦ hot air blower -VAS 1978/14A-
The brake servo -NX6- will henceforth be referred to as “brake
servo”.
For sealing plugs (assembly parts), see electronic parts cata‐
logue (ETKA)
1 - M10 sealing plugs
2 - M12 sealing plugs
Removing
– If the brake servo control unit -J539- is renewed, carry out
the test plan for the renewal of the brake servo control unit
-J539- using ⇒ Vehicle diagnostic tester .
– Remove battery tray ⇒ Electrical system; Rep. gr. 27; Bat‐
tery; Removing and installing battery tray .
– 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
– Extract as much brake fluid as possible from brake fluid res‐
ervoir -1- using brake filling and bleeding equipment -VAS
6860- -A- .
72
Rep. gr.47 - Brakes - hydraulics
ID.4 2021 ➤
Brake system - Edition 07.2021
– Disconnect electrical connector -2- from brake fluid level
warning contact -F34- and electrical connector -3- from
brake servo -1- .
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 brake
servo.
– Mark and unscrew brake lines -2- and -3- from brake master
cylinder.
2. Brake servo and brake master cylinder
73
ID.4 2021 ➤
Brake system - Edition 07.2021
– Seal threaded holes in brake master cylinder immediately
with M12 sealing plugs (assembly parts).
– Seal brake lines with engine bung set -VAS 6122- .
Note
Fit dust caps from bleeder screws on brake lines as an alterna‐
tive.
– ⇒ Rep. gr. 46; Separate brake pedal from brake servo .
– Unscrew nuts -3- and -4- for brake servo from mounting
bracket.
NOTICE
Risk of damage to the plenum chamber bulkhead due to im‐
proper separation of the bonded joint.
– Never lever the brake servo off the plenum chamber bulk‐
head to separate the bonded joint.
– If brake servo gets jammed in holes, loosen nuts -1- and -2-
on mounting bracket.
– Carefully pull brake servo off bulkhead, and remove it from
the vehicle.
Important
•
Make sure that the brake lines from brake master cylinder
are not bent.
– Remove adhesive residue -arrows- from brake servo -2- and
from bulkhead -1- .
74
Rep. gr.47 - Brakes - hydraulics
ID.4 2021 ➤
Brake system - Edition 07.2021
– To do this, apply gentle heat from hot air blower -VAS
1978/14A- to adhesive residue and pull it off.
– Thoroughly clean surfaces.
Install in reverse order of removal, observing the following:
– Renew gasket between brake servo and bulkhead.
– Insert brake servo, and screw on nuts by hand.
– ⇒ Rep. gr. 46; Connect brake pedal to brake servo .
– Use assembly tool -V.A.G 1410/8- to fit brake lines.
Important
•
Keep brake lines straight when fitting them.
– Tighten brake servo.
– ⇒ Rep. gr. 47; Bleed hydraulic system following standard
procedure .
– If the brake servo control unit -J539- has been renewed,
conclude the test plan for the renewal of the brake servo
control unit -J539- using ⇒ Vehicle diagnostic tester .
– Carry out basic setting of brake servo using ⇒ Vehicle diag‐
nostic tester .
Tightening torques
Assembling special tools for tightening brake lines
2. Brake servo and brake master cylinder
75
ID.4 2021 ➤
Brake system - Edition 07.2021
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. 47; Assembly overview – brake servo/brake mas‐
ter cylinder
♦ ⇒ Electrical system; Rep. gr. 27; Battery; Assembly over‐
view – battery
♦ ⇒ Heating, air conditioning system; Rep. gr. 87; Front heater
and air conditioning unit; Assembly overview – air intake unit
of heater and air conditioning unit
2.2.2
Removing and installing brake ser‐
vo [NX6], right-hand drive vehicles
Special tools and workshop equipment required
♦ 11 mm open ring spanner insert -V.A.G 1410/6-
♦ Socket set, 39-piece -VAS 6928-
♦ Torque wrench -VAS 6854-
♦ Universal joint -V.A.G 1410/7-
♦ assembly tool -V.A.G 1410/8-
♦ brake filling and bleeding equipment -VAS 6860-
♦ engine bung set -VAS 6122-
♦ hot air blower -VAS 1978/14A-
The brake servo -NX6- will henceforth be referred to as “brake
servo”.
For sealing plugs (assembly parts), see electronic parts cata‐
logue (ETKA)
1 - M10 sealing plugs
76
Rep. gr.47 - Brakes - hydraulics
ID.4 2021 ➤
Brake system - Edition 07.2021
2 - M12 sealing plugs
Removing
– If the brake servo control unit -J539- is renewed, carry out
the test plan for the renewal of the brake servo control unit
-J539- using ⇒ Vehicle diagnostic tester .
– 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
– Remove valve unit of heat pump ⇒ Heating, air conditioning
system; Rep. gr. 87; Heat pump valve unit; Removing and
installing heat pump valve unit
– Extract as much brake fluid as possible from brake fluid res‐
ervoir -1- using brake filling and bleeding equipment -VAS
6860- .
– Disconnect electrical connector -2- from brake fluid level
warning contact -F34- of brake fluid reservoir -1- .
– Remove stud -2- .
2. Brake servo and brake master cylinder
77
ID.4 2021 ➤
Brake system - Edition 07.2021
– Pull brake fluid reservoir -1- upwards out of brake master
cylinder.
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 brake
servo.
– Unscrew brake lines -2- and -3- from brake master cylinder
-1- .
– Seal threaded holes in brake master cylinder immediately
with M12 sealing plugs (assembly parts).
– Seal brake lines with engine bung set -VAS 6122- .
Note
Fit dust caps from bleeder screws on brake lines as an alterna‐
tive.
– ⇒ Rep. gr. 46; Separate brake pedal from brake servo .
– Unscrew nuts -3- and -4- for brake servo from mounting
bracket.
NOTICE
Risk of damage to the plenum chamber bulkhead due to im‐
proper separation of the bonded joint.
– Never lever the brake servo off the plenum chamber bulk‐
head to separate the bonded joint.
– If brake servo gets jammed in holes, loosen nuts -1- and -2-
on mounting bracket.
78
Rep. gr.47 - Brakes - hydraulics
ID.4 2021 ➤
Brake system - Edition 07.2021
– Carefully pull brake servo sideways to the left in direction of
travel until the gasket tears.
– Carefully pull brake servo off bulkhead.
– Disconnect electrical connector -1- from brake servo -2- .
– Remove brake servo from vehicle.
Important
•
Make sure that the brake lines from brake master cylinder
are not bent.
– Remove adhesive residue -arrows- from brake servo -2- and
from bulkhead -1- .
– To do this, apply gentle heat from hot air blower -VAS
1978/14A- to adhesive residue and pull it off.
– Thoroughly clean surfaces.
Installing
Install in reverse order of removal, observing the following:
– Renew gasket between brake servo and bulkhead.
– Insert brake servo, and screw on nuts by hand.
– ⇒ Rep. gr. 46; Connect brake pedal to brake servo .
– Use assembly tool -V.A.G 1410/8- to fit brake lines.
2. Brake servo and brake master cylinder
79
ID.4 2021 ➤
Brake system - Edition 07.2021
Important
Keep brake lines straight when fitting them.
•
– Tighten brake servo.
– ⇒ Rep. gr. 47; Bleed hydraulic system following standard
procedure .
– If the brake servo control unit -J539- has been renewed,
conclude the test plan for the renewal of the brake servo
control unit -J539- using ⇒ Vehicle diagnostic tester .
– Carry out basic setting of brake servo using ⇒ Vehicle diag‐
nostic 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. 47; Assembly overview – brake servo/brake mas‐
ter cylinder
♦ ⇒ Heating, air conditioning system; Rep. gr. 87; Front heater
and air conditioning unit; Assembly overview – air intake unit
of heater and air conditioning unit
♦ ⇒ Heating, air conditioning system; Rep. gr. 87; Heat pump
valve unit; Assembly overview – heat pump valve unit
80
Rep. gr.47 - Brakes - hydraulics
2024 VW ID.4 Owner's Manual
