Four Wheel ABS Hydraulic Control Unit (HCU)

Four Wheel Anti-Lock Brake System (4WABS) Hydraulic Control Unit (HCU)

Note: This procedure only needs to be performed if the 4-Wheel Anti-Lock Brake (4WABS) Hydraulic Control Unit (HCU) has been installed new or if the HCU lines have been opened.





1. C1ean all dirt from and remove the brake master cylinder filler cap, and fill the brake master cylinder reservoir with the specified brake fluid.





2. Connect a clear waste line to the RH rear bleeder screw and the other end in a container partially filled with recommended brake fluid.
3. Loosen the RH rear bleeder screw until a stream of brake fluid comes out. While the assistant maintains pressure on the brake pedal, tighten the RH rear bleeder screw.
- Repeat until clear, bubble-free fluid comes out.
- Refill the brake master cylinder reservoir as necessary.








4. Tighten the RH rear bleeder screw, and disconnect the waste line.





5. Repeat Steps 2, 3 and 4 for the LH rear bleeder screw, the RH front disc brake caliper bleeder screw, and the LH front disc brake caliper bleeder screw, in that order.





6. Connect the scan tool DCL cable adapter into the vehicle Data Link Connector (DLC) under the dash, and follow the scan tool instructions.
7. Repeat the system bleed procedure as outlined in Steps 1 through 5.