Hydraulic Control Assembly - Antilock Brakes: Service and Repair

HCU (HYDRAULIC CONTROL UNIT)

REMOVAL





1. Install prop rod on the brake pedal to keep pressure on the brake system.
2. Remove negative battery cable from the battery
3. Pull up on the ABM harness connector release (4) and remove connector.





4. Remove brake lines (1) from the ABM (2).
5. Remove ABM (2) mounting nuts (3) and remove ABM(2).

DISASSEMBLY





1. Remove the four screws (1) attaching the ABM module to the HCU (2).





2. Separate the ABM module (1) from the HCU (2).

ASSEMBLY





1. Clean any debris off the mating surfaces of the HCU and ABM module.

CAUTION: When installing new O-rings or solenoid valve stem seals, do not use any type of lubricant.

2. If the seals on the components are not new, they must be replaced. Each of the solenoid valve stem seals (1) must be replaced do not reuse solenoid valve stem seals.





3. The pump/motor connector O-ring (1) should also be replaced if not new





4. Align components and install the ABM module on the HCU.
5. Install the four screws attaching the ABM module to the HCU. Tighten the mounting screws to 2 Nm (17 inch lbs.) torque.
6. If the mounting bracket needs to be installed, install the mounting pins in the HCU as necessary and tighten to 11 Nm (97 inch lbs.) torque. Insert the mounting pins into the grommets mounted in the bracket, then install the single mounting bolt. Tighten the mounting bolt to 11 Nm (97 inch lbs.) torque.
7. Install the HCU in the vehicle.

INSTALLATION

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





1. Install ABM (2) on the mounting studs (3).
2. Install mounting nuts. Tighten to 14.1 Nm (125 inch lbs.).





3. Install brake lines (1) to the ABM (2) and tighten to 20 Nm (180 inch lbs.).





4. Install wiring harness connector (4) to the ABM (3) and push down on the release to secure the connector.
5. Install negative battery cable to the battery.
6. Bleed ABS brake system.