GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

The crankcase depression regulator valve is replaced as an assembly. Replace the hose, the pipe, and the grommet as required, if the inspection indicates cracks or decay.

Refer to the appropriate service information for the diesel crankcase ventilation system maintenance requirements.


    Object Number: 256069  Size: SH
  1. Remove the clamp (3) at the CDR valve (4).
  2. Disconnect the hose (5) from the CDR valve.
  3. Remove the CDR valve by pulling straight up.

Installation Procedure


    Object Number: 256069  Size: SH
  1. Install the CDR valve (4) into the valve cover.
  2. Connect the hose (5).
  3. 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.

  4. Install the clamp (3).
  5. Tighten
    Tighten the clamp to 1.7 N·m (15 lb in).