Volkswagen Golf Service & Repair Manual: General information
Repair instructions for repair work on ABS
| The ABS brake system is divided diagonally. The
servo-assistance is effected pneumatically by the vacuum brake
servo unit. |
| Vehicles with ABS are not fitted with a mechanical brake
pressure regulator. Specially developed software in the control
unit regulates the brake force distribution on the rear axle. |
 Note
| Faults in the ABS do not influence the brake system and
servo assistance. The conventional brake system remains
functional even without ABS. A change in braking behaviour is to
be reckoned with. After the ABS warning lamp comes on, the rear
wheels may lock prematurely during braking. |
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| ABS layout in LHD vehicles: |
| 1 - |
Hydraulic unit and control unit |
| The control unit and hydraulic are combined in a single
component. They can be separated only when removed. Hydraulic
pump must not be separated from hydraulic unit either. |
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| ABS layout in RHD vehicles: |
| 1 - |
Brake servo and brake master cylinder |
| 2 - |
ABS hydraulic unit -N55- and ABS control unit -J104- |
| The control unit and hydraulic are combined in a single
component. They can be separated only when removed. Hydraulic
pump must not be separated from hydraulic unit either. |
| Before carrying out repair work on the anti-lock brake
system, determine the cause of the fault as well as the control
unit code using “Guided Fault Finding”. |
| “Guided fault finding” is carried out using
→ Vehicle
diagnostic tester. |
| Disconnect battery earth strap with ignition switched off. |
| Before carrying out welding work with an electric welding
unit, note
→ General Information; Body Repairs, General Body Repairs. |
| When working with brake fluid, observe the relevant safety
precautions and notes
→ Chapter. |
| After work for which the brake system had to be opened,
bleed the brake system with brake filling and bleeding equipment
-VAS 5234-
→ Chapter. |
| During the final road test, ensure that a controlled brake
test is performed at least once (pulsations must be felt at the
brake pedal). |
| Absolute cleanliness is required when working on the
anti-lock brake system. Auxiliary items containing mineral oil,
e.g. oils, greases, etc. must never be used. |
| Thoroughly clean all unions and the adjacent areas before
loosening. Do not use aggressive cleaning agents such as brake
cleanser, petrol, thinners or similar. |
| Place removed parts on a clean surface and cover. |
| If repairs cannot be carried out immediately, carefully
cover or seal open components. (Use sealing plugs from repair
kit 1 H0 698 311 A). |
| Only use lint-free cloths. |
| Only unpack replacement parts immediately prior to fitting. |
| Only use genuine packed parts. |
| When the system is open, do not work with compressed air and
do not move the vehicle. |
| The valve coils in the control unit cannot be adjusted. |
| The valve coils in the control unit cannot be renewed. |
| Pressure sensor must not be changed or damaged. |
| The pressure sensor cannot be renewed. |
| The sensor housing must not be exposed to mechanical stress. |
| No measurements must be taken on contact points of control
unit. |
| No measurements must be taken on contact points of hydraulic
unit. |
| Contact pins of hydraulic unit must not be bent or damaged. |
| The contacts cannot be renewed. |
| No contact sprays may be used on the contacts or the
pressure sensor. |
| Foreign bodies must not get between the control unit and the
hydraulic unit. |
| During painting operations, the electronic control unit can
be exposed to a maximum temperature of 95°C for only a short
period, and to a maximum of 85°C for longer periods (approx.
2 hours). During longer periods (2 hours), the control unit can
be exposed to a maximum temperature of 85°C. Ensure that no
brake fluid enters connectors. |
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Overview of fitting locations - ABS/ESP
1 -
ABS control unit -J104-
Installation location: on hydraulic unit, on passenger side in
engine compartment.
...
Other materials:
Separating backrest cover from backrest padding
Note
Removal and installation is described for the left seat.
Apply the same instructions for removal and installation of
right seat components as appropriate.
Special tools and workshop equipment
required
...
Infrared heater -VAS 6876
Designation:
Infrared heater -VAS 6876-
Product description:
The infrared heater is used to dry putty, filler, base coat,
top coat and clear coat on vertical or horizontal surfaces.
...
Handling refrigerants
WARNING
Danger of freezing injuries.
The refrigerant can emerge as liquid or as vapour.
Do not open containers in which this refrigerant is
present.
...
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Overview of fitting locations