45-21
      
ABS hydraulic control unit, removing 
and installing 
 
     
Note:  
     When working with brake fluid, observe the 
relevant safety precautions and notes   Brake 
system, bleeding, page 47
-23
 . 
     
Special tools and equipment  
     
Sealing plugs from repair kit Part No. 1H0 698 
311A 
     Brake pedal depressor, e.g. from VAG1813
     
CAUTION! 
     
Part numbers are listed here for reference 
only. Always check with your Parts 
department for the latest information. 
      Component location:  
    
The hydraulic control unit is installed on the left side of the engine 
compartment.  
Pa
ge 4 of 6 Anti-lock Brake S
ystem 
(ABS
), Bosch 5.3
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.45.3 
         
        
        45-22
      
Removing  
     
CAUTION! 
     
Do not bend the brake lines.
     Before disconnecting the battery, determine 
the correct coding for the anti-theft radio. 
     
-  Disconnect battery Ground (GND) strap.
    
Note:  
The brake pedal depressor must remain in position until all of the brake 
lines have been reconnected to the hydraulic control unit.  -  Release control unit connector (arrow -1-) and disconnect harness 
connector (arrow -2-). 
-  Connect bleeder bottle to bleeder screw on left-front brake caliper and 
open bleeder screw. 
-  Install brake pedal depressor between brake pedal and driver's seat. 
Depress brake pedal by at least 60 mm (2 3/8 in.). 
-  Close left-front bleeder screw.
-  Cover engine compartment to make sure brake fluid does not flow into 
it. 
-  Disconnect brake line connections on hydraulic control unit.
Pa
ge 5 of 6 Anti-lock Brake S
ystem 
(ABS
), Bosch 5.3
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.SU03.45.3