Also called the hydraulic unit, the actuator contains the control solenoids for each brake circuit. The pump which maintains the system pressure during ABS braking is also within this unit. The control relay is mounted externally near the actuator. The ABS actuator can only be replaced as a unit; with the exception of the relay, individual components cannot be replaced.
Removal & Installation
- Disconnect the negative battery cable. Wait at least 90 seconds once the battery cable is disconnected before working on the vehicle. This will hinder the deployment of the air bags.
- Label and disconnect the electrical harnesses.
- Disconnect the hydraulic lines from the brake actuator. Plug the ends of the lines to prevent loss of fluid.
- Detach the hydraulic fluid pressure differential switch wiring connectors.
- Unfasten the nuts and remove the ABS actuator assembly.
- Before tightening the mounting nuts and bolts, screw the hydraulic line into the cylinder body a few turns.
- Install the actuator and tighten the ABS assembly bolts to 14 ft. lbs. (19 Nm).
- Attach and tighten the hydraulic lines to 11 ft. lbs. (15 Nm).
- Fill the brake master cylinder reservoir with new brake fluid. Bleed the system and check for leaks.