Volkswagen Golf Service & Repair Manual: Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

Volkswagen Golf Service & Repair Manual / Brake system / ABS, ADR, TCS, EDL, ESP / Control unit and hydraulic unit / Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

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:

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

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

Risk of damage to brake lines if bent.Never excessively 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.

–	Disconnect battery → Electrical system; Rep. gr.27

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

–	Remove heat shield -1- from mounting bracket -2-. To do this, release catches in -direction of arrow A-, and remove heat shield in -direction of arrow B-.

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

–	Press locking slide downwards in -direction of arrow A-.

–	Release connector -1- in -direction of arrow B-, and pull it off control unit.

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

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

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

–	Connect bleed bottle bleed hose -1- to bleed valve of front left brake caliper.

–	Open bleed valve.

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

–	Connect bleed hose of bleed bottle -1- to bleed valve of rear left brake caliper.

–	Open bleed 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-.

–	Place sufficient lint-free cloths under the control unit and hydraulic unit.

Note

Ensure no brake fluid gets onto the contacts of the control unit and the connector.

–	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 with part no. 5Q0 698 311.

–	Mark, unscrew and seal threaded holes of remaining brake lines (brake calipers).

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

–	Pull ABS hydraulic unit -N55- with mounting bracket -1- upwards in -direction of arrow- off retainer.

–	Remove ABS hydraulic unit -N55- with mounting bracket -1- upwards from vehicle.

Installing

Install in reverse order of removal, observing the following:

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 the rubber dampers are not pressed out of bracket.

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

Tightening sequence of brake lines:

–	Start brake line union screws in sequence -1- through -6-.

–	Tighten break line union screws in sequence -1- through -6-.

–	Remove brake pedal depressor -V.A.G 1869/2-.

–	Bleed brake system → Chapter.

–	Code radio.

–	Code control unit -J104- with → Vehicle diagnostic tester in "Guided Fault Finding" mode.

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-.

Specified torques

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

Connect battery → Electrical system; Rep. gr.27.

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

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

Removing and installing control unit and hydraulic unit, LHD vehicles, four-wheel drive, »R«

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