Hydraulic Control Assembly - Antilock Brakes: Service and Repair

REMOVAL PROCEDURE





CAUTION: For safety reasons, the Brake Pressure Modulator Valve (BPMV) must not be repaired, the complete unit must be replaced. With the exception of the EBCM/EBTCM, no screws may be loosened. If screws are loosened, it will not be possible to get the brake circuits leak-tight and personal injury may result.

NOTICE: The use of rubber hoses or parts other than those specified for the ABS may lead to functional problems requiring major overhaul.

1. Turn the ignition switch to the OFF position.
2. Remove the air cleaner assembly and the PCM cover.
3. Disconnect the following connectors:
^ The EBCM/EBTCM harness connector
^ The BPMV motor ground cable connector

IMPORTANT: Note the locations of the brake pipes in order to aid in installation.

4. Remove the front master cylinder brake pipe fittings from the BPMV.





5. Remove the top master cylinder brake pipe fittings from the BPMV.





6. Remove the wheel brake pipe fittings from the BPMV.

NOTICE: When removing the brake pressure modulator valve, protect the vehicle exterior from possible brake fluid spillage. Brake fluid can cause damage to painted surfaces.

NOTICE: Reposition brake pipes as necessary to remove brake pressure modulator valve. Excessive bending may cause damage to the pipes.

7. Clean any brake fluid spillage from the BPMV.





8. Remove the front EBCM/EBTCM bracket mounting bolt (4).
9. Remove the front EBCM/EBTCM bracket from the vehicle (5).





10. Remove the upper BPMV bracket from the frame rail (2).
11. Remove the two upper bracket to BPMV bolts (1).
12. Remove the EBCM/EBTCM and BPMV as an assembly.





13. Remove the 4 EBCM/EBTCM to BPMV bolts (1).

CAUTION: Do not pry EBCM/EBTCM. Be careful not to damage seal (if reusing module). If seal is damaged during removal, repair damaged area using GM P/N 123456739 silicone sealer or replace EBCM/EBTCM.

14. Pull rearward in order to separate the EBCM/EBTCM from the BPMV.

INSTALLATION PROCEDURE





1. Install the EBCM/EBTCM to the BPMV.
2. Clean the following surfaces with alcohol:
^ The EBCM/EBTCM seal
^ The BPMV

NOTICE: Refer to Fastener Notice in Service Precautions.

3. Install the EBCM/EBTCM to BPMV screws (1).
^ Tighten the screws to 4.5 Nm (40 inch lbs.).





IMPORTANT: It a new BPMV is being installed, remove the shipping plugs from the valve openings.

4. Install the upper BPMV bracket to the BPMV (2).
5. Install the EBCM/BPMV into the vehicle.
6. Install the 2 BPMV frame rail bolts.
^ Tighten the bolts to 12 Nm (106 inch lbs.).





7. Install the front EBCM/EBTCM bracket (5).
8. Install the EBCM/EBTCM to BPMV center bracket bolt (4).
^ Tighten the bolt to 14 Nm (10 ft. lbs.).





CAUTION: Make sure brake pipes are correctly connected to brake pressure modulator valve. If brake pipes are switched by mistake, wheel lockup will occur and personal injury may result The only two ways this condition can be detected are by using a Scan Tool or by doing an Antilock stop.

IMPORTANT: Use the locations noted during removal.

9. Install the wheel brake pipe fittings to the BPMV.
^ Tighten the brake pipe fitting at the BPMV to 16 Nm (12 ft. lbs.).





IMPORTANT: Use the locations noted during removal.

10. Install the top master cylinder brake pipe fittings to the BPMV.
^ Tighten the brake pipe fitting at the BPMV to 16 Nm (12 ft. lbs.).





IMPORTANT: Use the locations noted during removal.

11. Install the front master cylinder brake pipe fittings to the BPMV.
^ Tighten the brake pipe fitting at the BPMV to 16 Nm (12 ft. lbs.).

12. Connect the EBCM/EBTCM harness connector.
13. Connect the BPMV motor ground cable connector.
14. Install the air cleaner assembly and the PCM cover.
15. Fill and bleed the hydraulic brake system.
16. Turn the ignition ON leaving the engine OFF.
17. Perform the ABS Bleed Procedure.

NOTICE: Be sure to reconnect all harness retaining clips that may have been disconnected during the removal procedure in their original positions. Then perform a visual inspections of the entire harness checking to make sure all retaining clips are properly connected.

18. Perform the ABS Diagnostic System Check.