GM Service Manual Online
For 1990-2009 cars only

Tools Required

SA9116C EVO Power Steering Actuator Socket

Removal Procedure


    Object Number: 860255  Size: SH
  1. Disconnect negative battery cable.
  2. Remove pump from vehicle as previously described.
  3. Remove EVO electrical connector locating clip.
  4. Notice: Do not cock socket when removing EVO actuator, since this can result in actuator damage and loss of EVO operation.

  5. Remove EVO actuator assembly with theSA9116C (or equivalent).
  6. Remove discharge fitting from EVO actuator.
  7. Important: Note the size and location of each of the O-ring seals.

  8. Remove three O-ring seals from EVO actuator.

Installation Procedure


    Object Number: 860227  Size: SH
  1. Install the three O-rings in their correct locations.
  2. 1.1. Largest (19.00/18.54 mm ID) first
    1.2. Mid-size (17.4/16.44 mm ID) second
    1.3. Smallest (14.6/15.3 mm ID) third
  3. Install discharge fitting to EVO actuator until fully seated.
  4. Correctly position EVO actuator and discharge fitting to pump assembly.
  5. Notice: Refer to Fastener Notice in the Preface section.

  6. Using the SA9116C (or equivalent), tighten EVO actuator.
  7. Tighten
    Tighten Electronic Variable Orifice (EVO) Actuator to 62 N·m (46 lb ft).

  8. Position electrical connector so that it is in line with the pump shaft and pointing to the rear and install locating clip.
  9. Install pump as previously described.
  10. Connect negative battery cable.
  11. Tighten
    Tighten Battery Terminal Bolts to 17 N·m (13 lb ft).

  12. Bleed power steering system. Refer to Power Steering System Bleeding in Power Steering System.