GM Cadillac Deville_Fleetwood_ELD_Seville 1990-1998

Hydraulic Control Unit

Print

REMOVAL & INSTALLATION



1990 Vehicles
  1. Disconnect the negative battery cable.
  2.  
  3. Depressurize the hydraulic accumulator.
  4.  


CAUTION
The hydraulic accumulator contains brake fluid and nitrogen gas at extremely high pressures. It is mandatory that it be depressurized before disconnecting any brake lines, or personal injury may result.

  1. Label and detach all electrical connections at the hydraulic unit.
  2.  
  3. On Eldorado and Seville, remove the cross-car brace.
  4.  
  5. Remove the pump mounting bolt and move pump/motor assembly aside to allow access to the brake lines.
  6.  
  7. Using a backup wrench, disconnect the brake lines from the valve block.
  8.  
  9. Working inside the vehicle, disconnect the pushrod from the brake pedal. Push the dust boot forward, past the hex on the pushrod, and separate the pushrod into 2 sections by unscrewing it.
  10.  
  11. Remove the hydraulic unit mounting bolts at the pushrod bracket and remove the hydraulic unit from the vehicle. The front half of the pushrod will remain locked into the hydraulic unit.
  12.  

To install:

  1. Position the hydraulic unit in the vehicle and install new retaining bolts at the pushrod bracket. Tighten the bolts to 37 ft. lbs. (50 Nm).
  2.  
  3. From inside the vehicle, thread the pushrod halves together and tighten. Reposition the dust boot and connect the pushrod to the brake pedal.
  4.  
  5. Connect the brake lines to the valve block and tighten the fittings to 106 inch lbs. (12 Nm).
  6.  
  7. Position the pump/motor assembly on the hydraulic unit. Install the mounting bolt and tighten to 71 inch lbs. (8 Nm) on Deville and Fleetwood or 10 ft. lbs. (13 Nm) on Eldorado and Seville.
  8.  
  9. Install the cross-car brace, if removed.
  10.  
  11. Connect the electrical harness to the hydraulic unit.
  12.  
  13. Connect the negative battery cable.
  14.  
  15. Bleed the brake system.
  16.  



Click image to see an enlarged view

Fig. Hydraulic unit installation-1990 Eldorado and Seville; 1990 Deville and Fleetwood similar

1991-93 Deville and Fleetwood
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the air cleaner assembly.
  4.  
  5. Label and detach the wiring connectors at the PMV assembly. The connectors are for the fluid level switch, pump motor and valve block.
  6.  
  7. Loosen or reposition the clamp on the hose at the PMV reservoir.
  8.  
  9. Position a clean pan to catch any spilled fluid from the reservoir. Disconnect the hose from the reservoir and plug the hose with a 5 / 8 -inch (15.5mm) diameter plug.
  10.  
  11. Disconnect the primary and secondary brake lines at the PMV.
  12.  
  13. Disconnect the 4 brake lines from the PMV assembly.
  14.  
  15. Raise and safely support the vehicle.
  16.  
  17. Remove the lower PMV assembly retaining bolt.
  18.  
  19. Lower the vehicle to the ground.
  20.  
  21. Remove the harness strap, if equipped.
  22.  
  23. Support the PMV assembly and remove the upper retaining bolts. Remove the assembly from the vehicle. If the unit is being replaced with another, the reservoir and bracket(s) must be transferred to the new assembly.
  24.  


NOTE
The PMV assembly is not serviceable. Do not attempt to disassemble any part of the unit.

To install:

  1. Position the PMV assembly and install the upper retaining bolts. Tighten the bolts to 20 ft. lbs. (27 Nm).
  2.  
  3. Raise and safely support the vehicle. Install the lower retaining bolt and tighten it to 20 ft. lbs. (27 Nm). Lower the vehicle.
  4.  
  5. Connect the 4 brake lines to the PMV. Tighten the fittings to 11 ft. lbs. (15 Nm).
  6.  
  7. Install the primary and secondary brake lines, tightening each fitting to 11 ft. lbs. (15 Nm).
  8.  
  9. Connect the hose to the PMV reservoir and secure the clamp.
  10.  
  11. Connect the electrical connectors to the PMV assembly; make certain each connector is squarely seated and firmly retained.
  12.  
  13. Install the air cleaner assembly.
  14.  
  15. Connect the negative battery cable.
  16.  
  17. Fill the brake fluid reservoir and bleed the brake system.
  18.  
  19. Clean any spilled brake fluid from the PMV assembly and surrounding area to prevent damage to other components or paintwork.
  20.  



Click image to see an enlarged view

Fig. Pressure Modulator Valve (PMV) Assembly-1991-93 Deville and Fleetwood

1991-92 Eldorado and Seville
  1. Disconnect the negative battery cable.
  2.  
  3. Use a syringe or similar tool to remove the brake fluid from the master cylinder.
  4.  
  5. Remove the left front radiator brace and air cleaner intake hose.
  6.  
  7. Remove the modulator relay cover and detach the 12-way connector and modulator ground strap.
  8.  
  9. Label and disconnect the brake lines from the modulator. Plug the lines to prevent the entry of dirt and debris.
  10.  
  11. Remove the modulator mounting nuts and remove the modulator from the mounting bracket.
  12.  
  13. Remove the modulator mounting insulators and inspect them for damage. Replace as necessary.
  14.  

To install:

  1. Install the insulators on the modulator and install the modulator to the mounting bracket. Install the nuts and tighten to 8 ft. lbs. (11 Nm).
  2.  
  3. Connect the brake lines to the modulator and tighten the fittings to 9 ft. lbs. (12 Nm).
  4.  
  5. Connect the modulator connector and ground strap. Install the relay cover.
  6.  
  7. Install the air intake hose and radiator brace.
  8.  
  9. Fill the master cylinder reservoir with brake fluid and bleed the brake system.
  10.  



Click image to see an enlarged view

Fig. Hydraulic modulator-1991-92 Eldorado and Seville

1993-98 Eldorado and Seville; 1994-98 Deville


Click image to see an enlarged view

Fig. Brake Pressure Modulator-1993 Eldorado and Seville

  1. Disconnect the negative battery cable.
  2.  
  3. Raise and safely support the vehicle.
  4.  
  5. Remove the left front wheel and tire assembly.
  6.  
  7. Support the front of the cradle with a suitable jack.
  8.  
  9. Disconnect the exhaust pipe from the catalytic converter.
  10.  
  11. Remove the left front wheelwell splash shields.
  12.  
  13. Label and disconnect the brake lines from the modulator. Plug the lines to prevent the entry of dirt and debris.
  14.  
  15. Disconnect the brake line bundle from the left-hand frame rail.
  16.  
  17. Remove the bolts from the No. 1 and No. 2 body mounts. Loosen the No. 3 body mounts.
  18.  
  19. Using the jack, slowly lower the front cradle about 4-5 inches.
  20.  
  21. Remove the BPM valve cover.
  22.  
  23. Pull out (do not remove) the locking mechanism on the outer side of the ABS/TCS wiring harness connector. When 2 clicks are heard, the connector is completely disengaged and can be removed from the BPM valve.
  24.  
  25. Remove the TCS prime pipe, if equipped.
  26.  
  27. Disconnect the BPM ground strap.
  28.  
  29. Remove the BPM mounting nuts and remove the BPM through the left front wheelwell.
  30.  

To install:

  1. Install the BPM through the left front wheelwell and position it on the mounting bracket. Install the mounting nuts and tighten to 86 inch lbs. (10 Nm).
  2.  
  3. Connect the ground strap.
  4.  
  5. Connect the ABS/TCS wiring harness connector and install the BPM valve cover.
  6.  
  7. Connect the brake lines to the BPM and tighten the fittings to 13 ft. lbs. (18 Nm).
  8.  


CAUTION
Make sure the brake lines are connected to their proper locations. If the lines are switched by mistake (inlet vs. outlet), wheel lockup will occur and personal injury may result.

  1. Connect the TCS prime pipe, if equipped.
  2.  
  3. Raise the front cradle into position with the jack (do not over raise). Install the body mount bolts and tighten to 50 ft. lbs. (68 Nm).
  4.  
  5. Connect the brake line bundle to the left-hand frame rail.
  6.  
  7. Install the left front wheelwell splash shields.
  8.  
  9. Connect the exhaust pipe to the catalytic converter and tighten the bolts to 9 ft. lbs. (12 Nm).
  10.  
  11. Install the wheel and tire assembly and lower the vehicle.
  12.  
  13. Connect the negative battery cable.
  14.  
  15. Fill the master cylinder reservoir with brake fluid and bleed the brake system.
  16.  

 
label.common.footer.alt.autozoneLogo