Volkswagen Cars 2000-05

Hydraulic Control Module

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Removal & Installation



With Mark 20 ABS

NOTE
This procedure requires the use of a torque wrench and VAG 1869/2 Brake pedal depressor or equivalent pedal depressor tool.


NOTE
The ABS control module is bolted together with the hydraulic unit and is located in the left side of the engine compartment.


WARNING
Do NOT bend any of the brake lines around the hydraulic unit!

  1. If necessary, make sure you have the radio anti-theft code.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Detach the electrical connector from the Mass Air Flow (MAF) sensor from air filter tube.
  6.  
  7. Remove the bolts at the air filter (3), then move the filter to the left side.

    Click image to see an enlarged view

    Fig. Detach the electrical connector (1) from the Mass Air Flow (MAF) sensor from air filter tube. Remove the bolts (2) at the air filter (3), then remove the filter to the left side

  8.  
  9. On vehicles with Diesel engines, remove relay panel above brake booster.
  10.  
  11. Remove as much brake fluid as possible from brake fluid reservoir using a brake bleeder bottle.
  12.  
  13. Insert brake pedal depressor VAG 1869/2 or equivalent.
  14.  
  15. Activate brake pedal booster with brake pedal depressor.
  16.  
  17. Connect bleeder bottle hose to bleed screw of left front brake caliper and open bleed screw.
  18.  
  19. Close left front bleed screw.
  20.  
  21. Release the ABS control module connector and remove it.

    Click image to see an enlarged view

    Fig. Release the ABS control module connector (arrow 1) and remove it (arrow 2).

  22.  
  23. Place a suitable plastic covering under control module and hydraulic unit. Do not use rags.
    WARNING
    Do not let brake fluid enter electrical connectors.

  24.  
  25. Disconnect brake lines from hydraulic unit to brake master cylinder and suspend with wire.

    Click image to see an enlarged view

    Fig. Disconnect brake lines from hydraulic unit to brake master cylinder (arrows) and suspend with wire

  26.  
  27. Disconnect the remaining brake lines from hydraulic unit.
  28.  
  29. Plug or cap the brake lines and threaded holes.
  30.  
  31. Unfasten the bolts from the bracket for hydraulic unit.

    Click image to see an enlarged view

    Fig. Unfasten the bolts from the bracket for hydraulic unit (arrows)

  32.  
  33. Remove the hydraulic unit with control module as an assembly.
  34.  
  35. To remove the ABS control module from the hydraulic unit, perform the following:
    1. Detach the electrical connector for hydraulic pump motor from control module.
    2.  
    3. Remove the bolts from the control module and remove control module.
      NOTE
      When removing the control module make sure that the hydraulic unit valve dome does not contact the control module solenoid valves.



      Click image to see an enlarged view

      Fig. Remove the bolts (arrows) from the control module and remove the control module

    4.  

  36.  
  37. Cover the control module magnet coils with a plastic cover. Do not use rags.
  38.  
  39. After separating the control module and hydraulic unit, make sure you place them in a protected, covered place.

    Click image to see an enlarged view

    Fig. When removing the control module make sure that the hydraulic unit valve dome does not contact the control module solenoid valves

  40.  

To install:


NOTE
Only remove the sealing plugs on the new hydraulic unit just before installing the corresponding brake line. If the sealing plugs are removed from the hydraulic unit too early, brake fluid can escape. It can then no longer be guaranteed that the unit is sufficiently filled or adequately bled.

  1. When assembling the control module and hydraulic unit, be sure that the hydraulic unit valve dome does not come in contact with the control module solenoid valves.
  2.  
  3. Using new bolts, install control module to hydraulic unit. Do not tighten more than max. 4 Nm (35 in. lb).
  4.  
  5. Re-connect electrical connector for hydraulic pump motor.
  6.  
  7. Install ABS unit to bracket.
  8.  
  9. Hand-tighten bolts at first to make attaching the individual brake lines easier.
  10.  
  11. After tightening brake lines, tighten hydraulic unit.
  12.  
  13. The remainder of installation is the reverse of the removal procedure, noting the following tightening specifications:
    1. Control module to hydraulic unit: 35 inch lbs. (4 Nm) MAX
    2.  
    3. Hydraulic unit to bracket: 70 inch lbs. (8 Nm)
    4.  
    5. Master cylinder-to-brake booster nuts: 15 ft. lbs. (20 Nm)
    6.  
    7. Brake lines at ABS unit: 10 ft. lbs. (14 Nm)
    8.  
    9. Nut to body: 15 ft lbs. (20 Nm)
    10.  
    11. Cap nut to body: 15 ft. lbs. (20 Nm)
    12.  

  14.  
  15. Bleed the brake system, as outlined in this section.
  16.  
  17. Connect the negative battery cable.
  18.  
  19. Enter the radio code, if necessary.
  20.  

With Mark 60 ABS

NOTE
This procedure requires the use of a torque wrench and VAG 1869/2 Brake pedal depressor or equivalent pedal depressor tool.


NOTE
The ABS control module is bolted together with the hydraulic unit and is located in the left side of the engine compartment.


WARNING
Do NOT bend any of the brake lines around the hydraulic unit!

  1. If necessary, make sure you have the radio anti-theft code.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the air cleaner:
    1. Pull the connector from the Mass Air Flow (MAF) sensor.
    2.  
    3. Release the spring-type clip from the air duct hose with suitable pliers, then pull the hose off air cleaner.
    4.  
    5. Unfasten the air cleaner bolts and take out the air cleaner.

      Click image to see an enlarged view

      Fig. View of the spring clip (1), MAF sensor connector (2), air cleaner bolts (3) and air cleaner (4)

    6.  

  6.  
  7. Release the control module connector and pull the connector off.

    Click image to see an enlarged view

    Fig. Release the control module connector (arrow 1), then pull the connector off (arrow 2)

  8.  
  9. Install brake pedal loading device VAG 1869/2.
  10.  
  11. Connect bleeder bottle hose to left front brake caliper and left rear caliper bleed screw and open bleed screws.
  12.  
  13. Depress brake pedal at least 60 mm. (2.36 in.) with brake pedal depressor VAG 1869/2.
  14.  
  15. Close left front and left rear caliper bleeder screws.
    WARNING
    Do not remove brake pedal depressor VAG 1869/2 from brake pedal.

  16.  
  17. Place sufficient lint-free cloths under the control module and hydraulic unit.
    WARNING
    Make sure no brake fluid gets on contacts.

  18.  
  19. Disconnect the brake lines from hydraulic unit to brake master cylinder and tie up

    Click image to see an enlarged view

    Fig. Disconnect the brake lines (1) from the hydraulic unit and tie them out of the way. Location of the bolts (arrows) for the hydraulic unit

  20.  
  21. Disconnect the remaining brake lines from the hydraulic unit.
  22.  
  23. Plug or cap the brake lines and threaded holes to avoid contamination.
  24.  
  25. Remove bolts from hydraulic unit/control module bracket.
  26.  
  27. Remove hydraulic unit with control module.
  28.  
  29. To remove the control module from hydraulic unit:
    1. Place the hydraulic unit with control module down on a clean flat surface.
    2.  
    3. Remove E 5 hex socket head bolt from hydraulic pump.
      WARNING
      Do not separate the hydraulic pump from the hydraulic unit!

    4.  
    5. Tighten the hydraulic pump with the red bracket from the repair kit and two sealing plugs on the hydraulic unit.

      Click image to see an enlarged view

      Fig. Tighten the hydraulic pump with the red bracket (1) from the repair kit and two sealing plugs (2) on the hydraulic unit.

    6.  
    7. Separate hydraulic unit with hydraulic pump from control module by carefully lifting off joint.
      WARNING
      When pulling off control module, make sure that the hydraulic unit valve dome does not contact the control module solenoid valves.

    8.  
    9. Cover control module magnetic coils with a lint-free cloth.
    10.  
    11. After separating control module and hydraulic unit use transportation protection for valve dome.
    12.  
    13. The contact pin which is supplied as a replacement part along with the control module can only be clipped in once and then it cannot be removed.

      Click image to see an enlarged view

      Fig. The contact pin (2) which is supplied as a replacement part along with the control module can only be clipped in once and then it cannot be removed

    14.  

  30.  

To install:


NOTE
Only remove sealing plugs on new hydraulic unit when the corresponding brake line is going to be installed.


WARNING
If the sealing plugs are removed too early, brake fluid can escape, it can no longer be guaranteed that the module is sufficiently filled or adequately bled.


WARNING
When assembling the control module and hydraulic unit, be sure that the hydraulic unit valve dome does not come in contact with the control module solenoid valves.

  1. Using new bolts, install control module to hydraulic unit. Do not tighten more than a max. 4 Nm (35 in. lb).
  2.  
  3. Bolt ABS module to bracket. Do not tighten bolts completely. Attaching the individual brake lines is made easier.
  4.  
  5. After tightening brake lines, tighten hydraulic unit.
  6.  
  7. The remainder of installation is the reverse of the removal procedure, noting the following tightening specifications:
    1. Control module to hydraulic unit: 35 inch lbs. (4 Nm) MAX
    2.  
    3. Hydraulic unit to bracket: 70 inch lbs. (8 Nm)
    4.  
    5. Master cylinder-to-brake booster nuts: 15 ft. lbs. (20 Nm)
    6.  
    7. Brake lines at ABS unit: 10 ft. lbs. (14 Nm)
    8.  
    9. Cap nut to body: 15 ft. lbs. (20 Nm)
    10.  

  8.  
  9. Remove the rake pedal depressor.
  10.  
  11. Bleed the brake system.
  12.  
  13. Enter radio code.
  14.  

 
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