Antilock Brake System Hydraulic Unit Component Overview

WARNING:

• Always disconnect the battery ground strap.
• When removing and installing the brake lines, make sure the lines are marked and installed according to the identification on the ABS hydraulic unit.
• Install only original factory-made, pre-formed brake lines.
• Close brake lines and connections immediately with plugs.Brake line tightening torque is 15 Nm (11 ft lb). 
• After completing any work that requires opening the brake hydraulic system, bleed the brake system with brake filler and bleeder unit:VAS5234  .
• In addition, carry out a high- and low-pressure test of the brake system HIGH AND LOW PRESSURE, CHECKING .

Courtesy of AUDI OF AMERICA, LLC

1. Brake line
   • ABS hydraulic unit to right-rear brake caliper
   • Marking "HR" on ABS hydraulic unit
2. Brake line
   • ABS hydraulic unit to left-rear brake caliper
   • Marking "HL" on ABS hydraulic unit
3. Brake line
   • ABS hydraulic unit to right-front brake caliper
   • Marking "VR" on ABS hydraulic unit
4. Brake master cylinder
   • With brake booster
5. Brake lines
   • Brake master cylinder to ABS hydraulic unit
6. Bracket
   • Install ABS hydraulic unit and fasten
7. Cover
8. Brake line
   • ABS hydraulic unit to left-front brake caliper
   • Marking "VL" on ABS hydraulic unit
9. Wiring harness
10. ABS solenoid valve relay -J106-
11. ABS return flow pump relay -J105-
12. ABS hydraulic unit -N55-
    WARNING:

    • No repairs may be performed on the ABS hydraulic unit except replacement of the two relays. Do not loosen bolt connections.

    • Replace the ABS hydraulic unit only as a complete assembly, if necessary.

    • High and low pressure testing HIGH AND LOW PRESSURE, CHECKING 
13. Ground wire
    • Ensure good contact
14. Nut
    • 10 Nm (7 ft lb)
15. Washer
16. Serrated washer
17. Self-locking nut
    • Always replace
    • 7 Nm (62 in. lb)
18. Bearing bushing
19. Rubber mounting