On the Jetta, the hydraulic unit must be removed in order to access the ABS controller located on the bottom.

1) Remove plastic cover from the area around the ABS modulator (if any).

2) Depress brake pedal and keep down using a brake pedal depressor or equivalent.

3) Remove connector for air mass sensor. Unscrew bolts on air filter housing and place housing to the left side.

4) Place absorbent towel under the hydraulic unit in order to collect brake fluid.

5) Unscrew brake lines from brake master cylinder to hydraulic unit (arrows), and protect against dirt with caps from repair set 1HO698311A.

6) Tie up disconnected brake lines with wire, so that brake line ends are higher than brake fluid level in reservoir.

7) Make sure that no brake fluid enters the control module housing as this can lead to contact corrosion and result in system failure.

8) Remove controller connector. Unscrew bracket bolts and remove hydraulic unit.

9) Remove ABS controller. On Jetta's with Mark20 modules, remove the 4 hex screws that secure the module. On Mark60 modules (2002 and newer), you have to remove the two screws that secure the pump motor.

10) Re-install in reverse order.

11) Bleed the brake system.