Brake Pressure Modulator Valve Replacement

Brake Pressure Modulator Valve Replacement

Removal Procedure

Warning

The high pressure accumulator (HPA) and the chambers of the brake modulator assembly to which it attaches, store brake fluid at extremely high pressures. Fluid pressure must be relieved before attempting to service the HPA. Ensure that the recommended procedures are followed to relieve system pressure, including using the manual pressure release steps. Failure to properly follow procedures to depressurize the system may result in personal injury.

Warning: Refer to Brake Fluid Irritant Warning (Brake Fluid Irritant Warning).

Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution (Vehicle Damage Warnings).

Caution: Always connect or disconnect the wiring harness connector from the EBCM/EBTCM with the ignition switch in the OFF position. Failure to observe this precaution could result in damage to the EBCM/EBTCM.

Note: The ignition must be in the OFF position, without pausing at ACCESSORY, and without applying the brake pedal to ensure the brake modulator and high pressure accumulator (HPA) pressure relief occurs. This process will take approximately 1-3 minutes.

1. Turn the ignition to OFF, without pausing at ACCESSORY, and without applying the brake pedal.
Remove the ignition key.
2. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).
3. Clean all dirt and debris from the brake pressure modulator valve (BPMV) assembly and the brake pipe fittings.





Note: To ensure brake modulator and HPA pressure relief has occurred, the manual pressure relief valve must be opened momentarily.

4. Loosen the brake modulator manual pressure relief valve (1) 1/4 turn counterclockwise.
5. Seat, but do not tighten, the manual pressure relief valve.




6. Remove the BPMV bracket bolts (1).
7. Carefully slide the electronic hydraulic control unit rearward.
8. Lower the assembly slightly and support with heavy mechanics wire or equivalent.
9. Disconnect the electronic brake control module (EBCM) electrical connector.




10. Disconnect the BPMV supply hose quick connect (1).
Cap the BPMV inlet port and plug the supply hose to prevent brake fluid loss and contamination.
11. Disconnect the BPMV return hose quick connect (2).
Cap the BPMV outlet port and plug the return hose to prevent brake fluid loss and contamination.




12. Disconnect the primary brake pipe fitting (1).
Cap the brake pipe fitting and plug the BPMV inlet port to prevent brake fluid loss and contamination.
13. Disconnect the left front brake pipe fitting (2).
Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.
14. Disconnect the right front brake pipe fitting (3).
Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.




15. Disconnect the right rear brake pipe fitting (1).
Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.
16. Disconnect the left rear brake pipe fitting (2).
Cap the brake pipe fitting and plug the BPMV outlet port to prevent brake fluid loss and contamination.
17. Remove the BPMV module and bracket assembly from the vehicle.
18. Place the BPMV module and bracket assembly on a clean work surface.




19. Remove the 2 BPMV bolts (1).




20. Remove the BPMV module assembly from the bracket (1).
21. Remove the sleeves and insulators from the BPMV module, if necessary.




22. If replacing the BPMV, loosen but do not remove the EBCM bolts (1).





Note: Do not pry the EBCM from the BPMV. The EBCM must be pulled back evenly.

23. Using the loosened bolts as a guide, carefully pull the EBCM (1) evenly from the BPMV to release the electrical connectors.




24. Remove the EBCM bolts (1).




25. Remove the EBCM (1).

Installation Procedure




1. Install the EBCM (1) to the BPMV, if removed.





Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the EBCM bolts (1) and tighten in an X pattern to 3 Nm (27 lb in).




3. Install the sleeves and insulators to the BPMV module assembly, if removed.
4. Install the BPMV module assembly to the bracket (1).




5. Install the 2 BPMV bolts (1) and tighten to 9 Nm (80 lb in).
6. Position the BPMV module and bracket assembly to the vehicle underbody and support with heavy mechanics wire or equivalent.




7. Connect the right rear brake pipe fitting (1) and tighten to 18 Nm (13 lb ft).
8. Connect the left rear brake pipe fitting (2) and tighten to 18 Nm (13 lb ft).




9. Connect the primary brake pipe fitting (1) and tighten to 18 Nm (13 lb ft).
10. Connect the left front brake pipe fitting (2) and tighten to 18 Nm (13 lb ft).
11. Connect the right front brake pipe fitting (3) and tighten to 18 Nm (13 lb ft).




12. Connect the BPMV supply hose quick connect (1).
13. Connect the BPMV return hose quick connect (2).




14. Position the BPMV module and bracket assembly to the vehicle frame.
15. Install the BPMV bracket bolts (1) and tighten to 10 Nm (89 lb in).
16. Connect the EBCM electrical connector.




17. Tighten the brake modulator manual pressure relief valve (1) to 40 Nm (30 lb ft).
18. If installing a new EBCM, the EBCM must be programmed. Refer to Control Module References (Programming and Relearning).
19. Perform the Antilock Brake System Automated Bleed Procedure (Service and Repair).
Follow the procedure completely to ensure the sensor and boost valve calibration and EBCM learn processes have been completed.