Whenever service is performed on the Hydraulic Control Unit (HCU), a specific procedure must be performed to bleed the system to ensure that no air is trapped in the HCU. To perform this procedure, the New Generation Start (NGS) Tester, or an equivalent brake tool, is necessary.
REMOVAL & INSTALLATION
See Figure 1
- Disconnect the negative battery cable.
- Remove any components necessary for access to the HCU, located at the bottom of the right-hand side of the radiator in the engine compartment.
- Disengage the two wiring harness connectors from the HCU.
- Detach the five brake tubes from the HCU.
- Detach the HCU ground wire.
- Loosen the four mounting bolts, then remove the HCU from the vehicle.
- If necessary, separate the mounting bracket from the HCU by removing the three attaching nuts.
- If applicable, position the mounting bracket on the HCU and install the retaining nuts. Tighten the nuts to 88-176 inch lbs. (10-20 Nm).
- Position the HCU in the engine compartment and install the mounting bolts. Tighten the bottom bolts to 88-124 inch lbs. (10-14 Nm). Tighten the remaining bolts to 160-230 inch lbs. (18-26 Nm).
- Attach the HCU ground wire and attaching screw. Tighten the screw until snug.
- Reattach the five brake lines to the unit, then connect the negative battery cable.
- Bleed the brake system, as described later in this section.