The Brake Pressure Modulator Valve (BPMV) valve (formerly referred to as the Electro-Hydraulic Control Unit or EHCU) is mounted near or under the master cylinder and combination valve assemblies. The valve is not serviceable and must be replaced if malfunctioning. The valve is also the sight for the only additional attention required to properly bleed the 4WAL hydraulic system.
REMOVAL & INSTALLATION
See Figure 1
The EHCU/BPMV is not serviceable and must never be disassembled or repaired. If tests indicate the unit is faulty, the entire assembly must be replaced.
- Tag and disconnect the brake lines from the EHCU/BPMV. Immediately cap or plug all openings to prevent system contamination or excessive fluid loss.
- Tag and disengage the electrical connectors from the EHCU/BPMV.
- Remove the retainers holding the EHCU/BPMV upper bracket to the lower bracket and vehicle. Remove the upper bracket and hydraulic unit as an assembly.
- If necessary, once they are removed from the vehicle, separate the bracket from the EHCU/BPMV.
- If removed, assemble the EHCU/BPMV to its bracket. Install the retainers and tighten to 84 inch lbs. (9 Nm). Be careful, as overtightening these bolts can cause excessive noise transfer during system operation.
- Install the assembly into the vehicle, then tighten the retainers to 18-20 ft. lbs. (25-27 Nm).
- Attach the electrical connectors. Make certain each is squarely seated and secure.
- Remove the caps or plugs, then connect the brake lines to their original locations. Tighten the fittings to 16-21 ft. lbs. (25-29 Nm).
- Properly bleed the hydraulic brake system, including the EHCU/BPMV valve.