GM Service Manual Online
For 1990-2009 cars only

Crankcase Ventilation System Oil/Air Seperator Assembly

Removal Procedure


    Object Number: 12955  Size: SH
  1. Remove the Air cleaner outlet resonator. Refer to the Air Cleaner Outlet Resonator .
  2. Remove the intake manifold. Refer to the Engine Mechanical portion of the service manual.
  3. Disconnect the oil/air separator vent hoses (1) and (4).
  4. Remove the oil/air separator mounting bolts (2).
  5. Remove the oil/air separator assembly (3).

Installation Procedure


    Object Number: 12955  Size: SH
  1. Install the oil/air separator assembly (3).
  2. Install the oil/air separator mounting bolts (2).
  3. Tighten
    Tighten the Oil/Air separator mounting bolts to 20-28N·m (15-18 lb ft)

    Refer to the

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    in General Information.

    Important: When installing the hoses, apply a small film of soap to the inside edges of the hose prior to installation.

  4. Connect the oil/air separator vent hoses (1) and (4).
  5. Install the intake manifold. Refer to the Engine Mechanical portion of the service manual.
  6. Connect the Air cleaner outlet resonator. Refer to the Air Cleaner Outlet Resonator .