Note: For part numbers, see here.
The ABS unit is located in the engine compartment and is mounted on the right spar, near the front panel (see Figure 2, item 4 here).
ABS block: 1 – control unit; 2 – Right front brake pipe socket; 3 – rear left brake pipe socket; 4 – rear right brake pipe socket; 5 – Front left brake pipe socket; 6 – socket of the main brake cylinder tube; 7 – pump; 8 – hydraulic block (hydroelectric unit)
Removal
Place the vehicle on a two-post lift, apply the parking brake and turn off the ignition. Open the hood and disconnect the ground wire terminal from the battery.
Unscrew the three nuts securing the sound insulation to the front panel and the right mudguard and move the sound insulation aside to gain access to the hydraulic unit (flat head screwdriver).
Figure 21-1 - Removing the ABS hydraulic unit: 1 - hydraulic unit (block) ABS; 2 - front wiring harness mounting bracket on hydraulic unit bracket; 3 - brake pipe; 4 - front wiring harness; 5 - hydraulic unit bracket mounting bolts; 6 - Brake pipe mounting bracket on the hydraulic unit bracket; 7 - front wiring harness connector; 8 - hydraulic unit mounting bracket; 9 - ground wire mounting bracket on the hydraulic unit bracket; 10 - "ground" wire
Loosen the fittings and disconnect the brake pipes from the anti-lock brake system hydraulic unit. (key "11", or key for brake pipes type 41 08 11 13 f. "Stahlwille").
Install plugs into the hydraulic unit holes and onto the brake pipes.
Lifting the latch...
... disconnect the connector block 7, Figure 21-1, of the front wiring harness from the hydraulic unit.
Remove ground wire 10 from clamp 9 (figure 21-1).
Remove the front wiring harness from bracket 2 (picture below).
Remove the brake pipe from the mounting bracket 1 to the hydraulic unit bracket (picture below).
Loosen the bolts securing the hydraulic unit bracket to the body and remove the hydraulic unit (ABS hydraulic unit) complete with bracket (replaceable head 13, ratchet wrench).
Loosen the bolts securing the hydraulic unit to the mounting bracket and remove the hydraulic unit (replacement head 10, ratchet wrench).
Installation
Attention: When replacing the hydraulic unit, perform the ABS ECU parameter programming procedure.
Attention. To ensure tightness of the hydraulic unit control unit connector, the terminal of the hydraulic unit ground wire must be oriented downwards.
Install the hydraulic unit on the mounting bracket and secure with bolts. Tightening torque of bolts 8 Nm (0.8 kgf·m) (replacement head 10, ratchet wrench, torque wrench).
Install the hydraulic unit assembly with the bracket on the vehicle and secure with bolts. Tightening torque of bolts 22 Nm (2.2 kgf·m) (replaceable head 13, ratchet wrench, torque wrench).
Connect the front wiring harness plug to the hydraulic unit connector.
Install the wiring harness, ground wire and brake pipe into the mounting brackets on the hydraulic unit bracket (flat head screwdriver).
Remove the technological plugs from the openings of the hydraulic unit and brake pipes and connect the brake pipes to the hydraulic unit. Tightening torque of the fittings 14 Nm (1.4 kgf·m) (brake pipe wrench type 41 08 11 13 f. "Stahlwille", replaceable insert 11 type 58 23 10 11 f. "Stahlwille", torque wrench type 50 18 00 04 f. "Stahlwille").
Connect the ground wire terminal to the battery.
Bleed the brake system (see here).
Check the efficiency of the working brake system by test driving or on a test bench.