Volkswagen Golf Service & Repair Manual: Removing and installing control unit and hydraulic unit, LHD

Special tools and workshop equipment required

Torque wrench -V.A.G 1331-

Torque wrench -V.A.G 1410-

Brake pedal depressor -V.A.G 1869/2-

Sealing plugs, assembly part no. 5Q0 698 311

1 -	Sealing plug M10

2 -	Sealing plug M12

Removing

Location:

The control unit is bolted to the hydraulic unit and is located on right of the engine compartment.

Do not bend the brake lines in the area of the hydraulic unit!

Read out and note the existing control unit code.
If vehicle has a coded radio, note radio code or, if necessary, request it.
Observe safety precautions when working on the high-voltage system → Chapter.
Observe the risk classification of the high-voltage system → Electric drive; Rep. gr.00.
Disconnect battery → Electrical system; Rep. gr.27.
Remove catalytic converter → Rep. gr.26.

Remove heat shield -1- if present.
To do this, unclip heat shield -1- from bracket -2--arrow-.

Press down retainer catch -arrow A-.

Release electrical connector -arrow B-.
Pull off electrical connector -1-.

Apply brake pedal depressor -V.A.G 1869/2-.

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

Connect hose of bleeder bottle -1- to bleeder valve of rear left brake caliper.
Open bleeder valve.
Depress brake pedal at least 60 mm using brake pedal depressor -V.A.G 1869/2-.
Close front left and rear left bleeder valves.
Do not remove brake pedal depressor -V.A.G 1869/2-.

Note

Ensure no brake fluid gets onto contacts.

Pull cover off bulkhead and unclip brake lines.
First identify both brake lines from brake master cylinder and unscrew from hydraulic unit.
Seal threaded holes immediately using sealing plugs from the assembly part kit, part no. 5Q0 698 311.
Mark, unscrew and seal threaded holes of remaining brake lines (brake calipers).

Pull hydraulic unit together with control unit upwards out of dampers -arrow-.

Installing

Install in reverse order. Note the following points:

Note Remove sealing plugs from new hydraulic unit only when the corresponding brake line is to be fitted. If sealing plugs are removed too early from the hydraulic unit, brake fluid can escape, and it can then no longer be guaranteed that the unit can be sufficiently filled and bled. When installing the hydraulic unit, ensure that rubber dampers are not pressed out of bracket.

Tightening sequence of brake lines:

Remove brake pedal depressor -V.A.G 1869/2-.
Bleed brake system → Chapter.
Code radio.
Code control unit -J104- using → Vehicle diagnostic tester in "Guided Fault Finding".

To do this, carry out basic setting of the steering angle sender -G85-, the lateral acceleration sender -G200-, the longitudinal acceleration sender -G251- and the brake pressure sender -G201-.

Removing and installing control unit and hydraulic unit, LHD

Special tools and workshop equipment required

Torque wrench -V.A.G 1331-

Torque wrench -V.A.G 1410-

Brake pedal depressor -V.A.G 1869/2-

Sealing plugs, assembly part no. 5Q0 698 311

Removing

Location:

Do not bend the brake lines in the area of the hydraulic unit!

Ensure no brake fluid gets onto contacts.

Installing

Install in reverse order. Note the following points:

Tightening sequence of brake lines:

Specified torques

→ Chapter „Assembly overview - control unit and hydraulic unit, LHD vehicles“

→ Rep. gr.26

Battery → Electrical system; Rep. gr.27

Front bleeder valves → Chapter „Assembly overview - front brake caliper“

Rear bleeder valves → Chapter „Assembly overview - rear brake caliper“

Test yourself