Antilock Brakes / Traction Control Systems: Service and Repair

HYDRAULIC CONTROL UNIT (HCU) REMOVAL/INSTALLATION





Warning
^ Carefully read cautionary information on product label. For EMERGENCY MEDICAL INFORMATION seek medical advice. For additional information, consult the product Material Safety Data Sheet (MSDS) if available. Failure to follow these instructions may result in personal injury.

Caution
^ Brake fluid is harmful to painted and plastic surfaces. If brake fluid is spilled onto a painted or plastic surface, immediately wash it with water.

Caution
^ Electronic modules are sensitive to electrical charges. The anti-lock brake system (ABS) module can be damaged if exposed to these charges.

Note
^ When installing a new ABS module/hydraulic control unit (HCU) assembly, it must be configured (either by download/upload or uploading the As-Built data method).

Note
^ On vehicles equipped with roll stability control (RSC), the ABS module is available separately from the HCU and should be serviced separately. However, if the RSC-equipped vehicle requires a new HCU, then the ABS module and the HCU must be installed as an assembly. Make sure to use the most recently released service parts.

Removal/installation

All Vehicles
1. Disconnect the battery ground cable.
2. Remove the air cleaner and the air cleaner outlet pipe.
3. Disconnect the master cylinder brake tube fittings from the hydraulic control unit (HCU).
^ To install, tighten to 23 N-m (2.3 kgf-m, 17 ft-lbf).

Vehicles With 3.0L (4V) Engine
4. Disconnect the master cylinder brake tube fittings from the master cylinder and remove the brake tubes.
^ To install, tighten to 23 N-m (2.3 kgf-m, 17 ft-lbf).

All Vehicles
5. Disconnect the front brake tube fittings from the HCU.
^ To install, tighten to 15 N-m (1.5 kgf-m, 11 ft-lbf).
6. Disconnect the rear brake tube fittings from the jumper tubes.
^ To install, tighten to 15 N-m (1.5 kgf-m, 11 ft-lbf).





7. Disconnect the electrical connector by rotating the protective cover.
8. Remove the 3 HCU bracket-to-frame bolts and remove the HCU.
^ To install, tighten to 23 N-m (2.3 kgf-m, 17 ft-lbf).
9. To install, reverse the removal procedure.
^ Bleed the brake system.