GM S-Series Pick-ups and SUV's 1994-1999 Repair Guide

Component Replacement



See Figures 1 and 2

The EHCU/BPMV valve is not serviceable and must never be disassembled or repaired. If tests indicate the unit is faulty, the entire assembly must be replaced.

  1. Tag and disconnect the brake lines from the EHCU/BPMV. Immediately cap or plug all openings to prevent system contamination or excessive fluid loss.
  3. Tag and unplug the electrical connectors from the EHCU/BPMV.

Click image to see an enlarged view

Fig. Fig. 1: Brake Pressure Modulator Valve (BPMV) mounting

Click image to see an enlarged view

Fig. Fig. 2: EHCU/BPMV brake pipe connections-ALWAYS tag the connections to assure proper installation

  1. 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.
  3. If necessary, once they are removed from the vehicle, separate the bracket from the EHCU/BPMV.

To install:
  1. 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.
  3. Install the assembly into the vehicle, then tighten the retainers 18 ft. lbs. (25 Nm).
  5. Engage the electrical connectors as tagged during removal. Make certain each is squarely seated and secure.
  7. Remove the caps or plugs, then connect the brake lines to their original locations, as tagged during removal. Tighten the fittings to 21 ft. lbs. (29 Nm ).
  9. Properly bleed the hydraulic brake system, including the EHCU/BPMV valve.