Volkswagen Golf Quiz
Brake system

Removing and installing control unit and hydraulic unit, RHD vehicles

In this manual: Brake system
General body repairs, exterior — 230General body repairs, interior — 279General information, paint — 133Vechile- specific paint information — 27Heating, air conditioning — 156Auxiliary heater — 58Air conditioning system with refrigerant R134a — 1297- speed dual clutch gearbox 0CW — 544- cylinder injection engine(1.4 1 direct inction. turbocharger) — 182Fuel supply system - Petrol engines — 59Running gear, axles, steering — 221Brake system — 92Wheels and Tyres guide — 12Guide for using trailers — 11Wheels and Tyres Guide - General Information — 121Brake system (hybrid) — 73Electrical system — 326Communication — 65Electrical system, general information — 111
~3min read
Removing and installing control unit and hydraulic unit, RHD vehicles

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
Removing and installing control unit and hydraulic unit, RHD vehicles
Fitting location of ABS hydraulic unit -N55- and ABS control unit -J104- in RHD vehicles:
1 - Brake servo and brake master cylinder
2 - ABS hydraulic unit -N55- and ABS control unit -J104-
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
  • Remove battery tray -1- → Electrical system; Rep. gr.27.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • Apply brake pedal depressor -V.A.G 1869/2-.
  • Remove noise insulation → General body repairs, exterior; Rep. gr.66.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • Press down retainer catch -arrow A-.
Note The illustration shows installation position of ABS hydraulic unit -N55- and ABS control unit -J104- on a LHD vehicle.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • Release electrical connector -arrow B-.
  • Pull off electrical connector -1-.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • 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, RHD vehicles
  • 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 sufficiently lint-free cloths under ABS control unit -J104- and ABS hydraulic unit -N55-.
Note Make sure no brake fluid gets onto electrical contacts on ABS control unit -J104-.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • First, mark the two brake lines -A- and -B- coming from brake master cylinder.
  • Disconnect the two brake master cylinder brake lines -A- and -B- from ABS hydraulic unit -N55-.
  • Seal threaded holes immediately using sealing plugs from the assembly part kit with part no. 5Q0 698 311.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • Mark and unscrew remaining brake lines (brake calipers). Seal threaded holes -2-.
Removing and installing control unit and hydraulic unit, RHD vehicles
  • Pull off ABS hydraulic unit -N55--1- together with bracket -2- in -direction of arrow-.
  • The rubber dampers -arrows- will be pulled off the studs of bracket -3- while doing so.
  • Guide hydraulic unit out of 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.

Do not bend the brake lines in the area of the ABS hydraulic unit -N55-

Ensure that rubber dampers of retainer are not pressed out of bracket when installing. After installation, check that the ABS hydraulic unit -N55- is firmly seated, or malfunction can occur.
Removing and installing control unit and hydraulic unit, RHD vehicles

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 ABS control unit -J104- using → Vehicle diagnostic tester.
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, RHD vehicles“

Battery → Electrical system; Rep. gr.27

Noise insulation → General body repairs, exterior; Rep. gr.66.

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, RHD vehicles

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