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Assembly overview: Servo unit/brake master cylinder > < Bleeding brake system without brake filling and bleeding unit

A2

Brake System
Bleeding brake system
Initiating basic setting

Special tools and workshop equipment required
 
W00-0457
  • ◆ → V.A.G 1869 Brake filling and bleeding unit

Function 04 "Initiate basic setting" fulfils several tasks:

  • ◆ Display group number 001 is only required for the bleeding of the hydraulic unit. .

Basic setting is only necessary if at least one chamber of the brake fluid reservoir is completely empty (e.g. in the event of leakage in the brake system).

Display group number 01: Bleeding the hydraulic unit.

When filling up brake fluid with a filling and bleeding unit, e.g. V.A.G 1869, make sure that the filling pressure of 1 bar is not exceeded.

If the filling pressure exceeds 1 bar a hydraulically controlled changeover valve, which is required for the EDL function, prevents unrestricted flushing of the EDL-related parts of the hydraulic unit. If this is the case, it may not be possible to bleed the system properly.

For this reason the brake fluid pressure must be reduced to 1 bar on filler and bleeder units VW 1238/1 and V.A.G 1869.

=> Operating instructions VW 1238/1, V.A.G 1869

Filling and bleeding unit V.A.G 1238/B is not suitable for bleeding brake system for "Initiate basic setting" function.

If only filler and bleeder unit V.A.G 1238/B is available then switch unit on and off to ensure that there is always sufficient brake fluid in the reservoir.

  • ‒ Connect filler and bleeder unit, e.g. V.A.G 1869.
  • ‒ Connect fault reader V.A.G 1551 and select "Brake electronics" with address word 03.
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Press keys 0 and 4 to select function "Basic setting".
 
→ Indicated on display:
Rapid data transfer     Q
04 - Basic setting
  • ‒ Confirm input with Q key.

Note:

During the next test steps the ABS warning lamp flashes 4 times per second.
 
→ Indicated on display:
Default setting    HELP
Enter display group number XXX
  • ‒ Press keys 0, 0 and 1.
  • ‒ Confirm input with Q key.

The following test cycle must be repeated 8 times according to the prescribed sequence in the basic setting mode on V.A.G 1551.
 
→ Indicated on display:
System in basic setting     1
Press and hold brake pedal...
  • ‒ Operate pedal with substantial foot pressure and hold.

Notes:

  • ◆ Pedal moves down
  • ◆ Hydraulic pump runs
  • ◆ Pedal comes back
 
→ Indicated on display:
System in basic setting     1
Release pedal; FR+FL Bleeder screw ON
  • ‒ Press key 3.
 
→ Indicated on display:
System in basic setting     2
wait...    
  • ‒ Wait 10 seconds.
 
→ Indicated on display:
System in basic setting     2
Press pedal 10x; Bleeder screw CLOSED
  • ‒ Press key 3.
 
→ If all eight cycles have been completed, the following display appears:
System in basic setting     17
Part bleeding ended ...
  • ‒ Press ⇒key.
 
→ Indicated on display:
Rapid data transfer     HELP
Select function XX
  • ‒ Press keys 0 and 6 for the function "End output".
 
→ Indicated on display:
Rapid data transfer     Q
06 - End output
  • ‒ Confirm input with Q key.
 
→ Indicated on display:
Rapid data transfer    HELP
Enter address word XX
  • ‒ Press Ckey.
  • ‒ Switch ignition off.
  • ‒ Disconnect fault reader.
  • ‒ The brake system must subsequently be bled .

Assembly overview: Servo unit/brake master cylinder > < Bleeding brake system without brake filling and bleeding unit