Volkswagen ID.4: Control unit and hydraulic unit

• Assembly overview - control unit and hydraulic unit
• Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55]
• Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55], right-hand drive vehicles

Assembly overview - control unit and hydraulic unit

Assembly overview - control unit and hydraulic unit, left-hand drive vehicles

1. ABS control unit -J104-

• ⇒ Rep. gr. 45; Removing 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
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

3. Brake line to brake caliper, front left

• 5.25 mm in diameter and union screw with M10 × 1 thread
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

4. Brake line to brake caliper, front right

• 5.25 mm in diameter and union screw with short M12 × 1 thread
• With commercially available standard tool: 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
• With commercially available standard tool: 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

8. Brake line to secondary piston circuit of brake master cylinder

• 6 mm in diameter and union screw with M12 × 1 thread
• With commercially available standard tool: 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

• 6 mm in diameter and union screw with M12 × 1 thread
• With commercially available standard tool: 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-

• ⇒ 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

Installing ABS control unit -J104- - specified torque and tightening sequence

Assembly overview - control unit and hydraulic unit, right-hand drive

1. Brake line to rear right wheel brake cylinder

• 5.25 mm in diameter and union screw with short M12 × 1 thread
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

2. Brake line to brake caliper, front left

• 5.25 mm in diameter and union screw with M10 × 1 thread
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

3. Brake line to brake caliper, front right

• 5.25 mm in diameter and union screw with short M12 × 1 thread
• With commercially available standard tool: 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
• With commercially available standard tool: 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
• With commercially available standard tool: 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
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

7. Torx bolt

• Thread-forming
• Qty. 4
• Renew after removing

8. ABS hydraulic unit -N55-

• ⇒ Rep. gr. 45; Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55]

9. Bracket
10. Bolt

• Qty. 2
• 20 Nm

11. Bolt

• 20 Nm

12. Rubber mounting

• Qty. 3

13. Mounting bracket
14. Bolt

• Qty. 2
• 8 Nm

15. ABS control unit -J104-

• ⇒ Rep. gr. 45; Separating control unit from and connecting to hydraulic unit

16. Brake line from secondary piston circuit to hydraulic unit

• 6 mm in diameter and union screw with M12 × 1 thread
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

17.  Brake line from primary piston circuit to hydraulic unit

• 6 mm in diameter and union screw with M12 × 1 thread
• With commercially available standard tool: 14 Nm
• With special tools VAS 6854, VAG 1410/7 and VAG 1410/6: 12 Nm

18.  Brake servo -NX6-

•  ⇒ Rep. gr. 47; Assembly overview - brake servo/brake master cylinder
• ⇒ Rep. gr. 47; Removing and installing brake servo

Installing ABS control unit -J104- - specified torque and tightening sequence

Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55]

Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55], left-hand drive vehicles

Special tools and workshop equipment required

• Engine bung set -VAS 6122-
• Open ring spanner insert, AF 11mm -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-

For sealing plugs (assembly parts), see electronic parts catalogue (ETKA)

Removing

ABS control unit -J104- -1- is referred to hereafter as control unit.

ABS hydraulic unit -N55- -2- is referred to hereafter as hydraulic unit.

• 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.
• Disconnect battery ⇒ Electrical system; Rep. gr. 27; Battery; Disconnecting and connecting battery.
• Push locking mechanism 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-.

• Connect bleeder hose of first bleeder bottle to bleeder valve of front left brake caliper -1-.
• Open bleeder valve.

• Connect bleeder hose of second bleeder bottle to bleeder screw of rear left wheel brake cylinder -1-.

• Open bleeder valve.
• Depress brake pedal at least 60 mm using brake pedal actuator -V.A.G 1869/2-.
• Close front left and rear left bleeder valves.
• Do not remove brake pedal actuator -V.A.G 1869/2-.

NOTICE

Risk of damage to brake lines when bending.

• Do not adjust curve of brake lines in area of hydraulic unit.

• Unclip brake lines at bulkhead.

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.

• Mark brake lines -5- and -6- and unscrew from hydraulic unit.

• Seal threaded holes with 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

As an alternative, fit dust caps of bleeder valves onto brake lines.

• Pull out hydraulic unit and control unit -1- together with bracket -3- and rubber mountings -4- 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.

Important

• When installing hydraulic unit, rubber bushes must not pressed out of bracket.

• Use assembly tool -V.A.G 1410/8- to fit brake lines in the sequence -1- to -6-.

• Tighten break lines in the sequence -1- to -6-.
• Remove brake pedal actuator -V.A.G 1869/2-.
• ⇒ Rep. gr. 47; Bleed hydraulic system.

If the ABS control unit -J104- has been renewed, perform the test plan for renewal of the control unit:

• Carry out function "Renew control unit" using ⇒ Vehicle diagnostic tester ⇒ Rep. gr. 00; Access to diagnoses.

Continued

Tightening torques

Assembling special tools for tightening brake lines

1. Torque wrench -VAS 6854-
2. Universal joint -V.A.G 1410/7-
3. Open ring spanner insert AF 11 -V.A.G 1410/6-

• ⇒ Rep. gr. 45; Assembly overview - control unit and hydraulic unit
• ⇒ Rep. gr. 46; Assembly overview - front brake
• ⇒ Rep. gr. 46; Assembly overview - brake shoes
• ⇒ Electrical system; Rep. gr. 27; Battery; Assembly overview - battery

Removing and installing ABS control unit [J104]/ABS hydraulic unit [N55], right-hand drive vehicles

Special tools and workshop equipment required

• Engine bung set -VAS 6122-
• Open ring spanner insert, AF 11mm -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-

For sealing plugs (assembly parts), see electronic parts catalogue (ETKA)

Removing

ABS control unit -J104- is called control unit in this manual.

ABS hydraulic unit -N55- is called hydraulic unit in this manual.

• Remove battery tray ⇒ Electrical system; Rep. gr. 27; Battery; Removing and installing battery tray.
• Push locking mechanism 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-.

• Connect bleeder hose of first bleeder bottle to bleeder valve of front left brake caliper -1-.

• Connect bleeder hose of second bleeder bottle to bleeder screw of rear left wheel brake cylinder -1-.

• Depress brake pedal at least 60 mm using brake pedal actuator -V.A.G 1869/2-.
• Close front left and rear left bleeder valves.
• Do not remove brake pedal actuator -V.A.G 1869/2-.

NOTICE

Risk of damage to brake lines when bending.

• Do not adjust curve of brake lines in area of hydraulic unit.
• Unclip brake lines at bulkhead.

NOTICE

Risk of damage due to corrosion.

• Ensure that no brake fluid gets onto electrical contacts.
• Place sufficient lint-free cleaning cloths in area of electrical connectors.

• Mark brake lines -5- and -6- and unscrew from hydraulic unit.

• Seal threaded holes with 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

Alternatively, fit dust caps of bleeder valves onto brake lines.

• Pull out hydraulic unit and control unit -1- together with bracket -3- and rubber mountings -4- 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.

Important

• When installing hydraulic unit, rubber bushes must not pressed out of bracket.

• Use assembly tool -V.A.G 1410/8- to fit brake lines in the sequence -1- to -6-.

• Tighten break lines in the sequence -1- to -6-.
• Remove brake pedal actuator -V.A.G 1869/2-.
• ⇒ Rep. gr. 47; Bleed hydraulic system.

If the control unit has been renewed, carry out the test plan for renewal of control unit:

• Carry out function "Renew control unit" using ⇒ Vehicle diagnostic tester ⇒ Rep. gr. 00; Access to diagnoses.

Continued

Tightening torques

Assembling special tools for tightening brake lines

1. Torque wrench -VAS 6854-
2. Universal joint -V.A.G 1410/7-
3.  Open ring spanner insert AF 11 -V.A.G 1410/6-

• ⇒ Rep. gr. 45; Assembly overview - control unit and hydraulic unit
• ⇒ Rep. gr. 46; Assembly overview - front brake
• ⇒ Rep. gr. 46; Assembly overview - brake shoes
• ⇒ Electrical system; Rep. gr. 27; Battery; Assembly overview - battery