Hydraulic Control Assembly - Antilock Brakes: Service and Repair

Hydraulic Control Unit (HCU)

Removal and Installation

WARNING: Brake fluid contains polyglycol ethers and polyglycols. Avoid contact with eyes. Wash hands thoroughly after handling. If brake fluid contacts the eyes, flush the eyes with running water for 15 minutes. Get medical attention if irritation persists. If taken internally, drink water and induce vomiting. Get medical attention immediately. Failure to follow these instructions may result in personal injury.

WARNING: When installing a new hydraulic control unit (HCU) and stability assist module, the HCU and stability assist module must be removed as a complete assembly. Failure to follow these instructions may result in personal injury.

CAUTION: Use of any other than approved DOT brake fluid will cause permanent damage to brake components and will render the brakes inoperative.

CAUTION: Brake fluid is harmful to painted or plastic surfaces. If brake fluid is spilled onto a painted or plastic surface, immediately rinse it off with water.

1. Disconnect the battery.





2. Disconnect the low brake fluid warning indicator switch electrical connector.
1 Pull back the tab.
2 Press the clips.
3 Disconnect the electrical connector.





3. CAUTION: Make sure the filler cap does not become contaminated.

Remove the reservoir filler cap.

4. Remove the front wheels.





5. Loosen the bleeder screw.
1 Remove the bleeder screw cap.
2 Loosen the bleeder screw.





6. NOTE: Carry out this process on both the front brake lines.

Drain the brake fluid reservoir.
1 Connect a bleed tube to the bleeder screw and into a suitable container.
2 Press the brake pedal until the no more fluid is expelled.
3 Tighten the bleeder screw.
7. Lower the vehicle.
8. Install the brake fluid reservoir cap.
9. Remove the air cleaner.
10. Remove the air cleaner outlet tube.





11. Disconnect the electrical connector.





12. Remove the battery Junction box (BJB).





13. Disconnect the BJB from the bracket and position aside.
^ Press the locking tabs.





14. Disconnect the ABS module electrical connector.
1 Release the retainer.
2 Disconnect the electrical connector.





15. ZCAUTION: Cap the brake tube connections to prevent fluid loss or dirt contamination.

Disconnect the HCU brake tubes.





16. Unclip the brake tubes.





17. CAUTION: Cap the brake tube connections to prevent fluid loss or dirt contamination.

Remove the master cylinder to HCU brake tubes.





18. Disconnect the wiring harness from the wheelhouse assembly.





19. Remove the HCU bolts and separate the HCU from the support bracket.

20. NOTE: After installation, bleed the brake system.

To install, reverse the removal procedure.