Hydraulic Control Assembly - Antilock Brakes: Service and Repair

HCU (HYDRAULIC CONTROL UNIT)

REMOVAL
1. Remove the negative battery cable from the battery.
2. Install a brake pedal prop rod.
3. Siphon the master cylinder.





4. Remove the primary brake line at the master cylinder.
5. Remove the primary brake line from the HCU (4).
6. Remove the secondary brake tube at the master cylinder.
7. Remove the secondary brake tube at the HCU (4).
8. Remove the 4 chassis lines (3) at the HCU (4).





9. Disconnect the HCU (4) electrical connectors (5).





10. Remove the mounting nuts at the HCU bracket (5).
11. Remove the HCU (3) with the bracket (5) from the vehicle.





12. Remove the 3 ABM. bolts securing the ABM. (1) to the HCU (2).

INSTALLATION

NOTE: If the ABM is being replaced with a new ABM is must be reprogrammed with the use of a scan tool.





1. Install the 3 ABM. (1) mounting bolts to the HCU (2) if removed tighten mounting bolts to 12 Nm (9 ft. lbs.).





2. Install the HCU (3) with bracket (5) to the vehicle and tighten the 2 mounting nuts.





3. Install the 4 chassis lines (3) at the HCU (4).
4. Install the secondary brake line at the HCU (4).
5. Install the secondary brake line at the master cylinder.
6. Install the primary brake line at the HCU (4).
7. Install the primary brake line at the master cylinder.





8. Reconnect the HCU (4) electrical connector (5).
10. Remove the brake pedal prop rod.
11. Bleed base and ABS brake systems.