GM Service Manual Online
For 1990-2009 cars only

Before Bleeding the Power Steering System

Bleed the power steering system under the following conditions:

    • After component replacement
    • After disconnecting the fluid line
    • In order to detect steering system noise

Bleed the power steering system in order to prevent the following conditions:

    • Pump damage
    • Improper system operation
    • Steering system noise

Before bleeding the air from the power steering system, inspect the following conditions:

    • Ensure that the hoses do not touch any other part of the vehicle that may cause steering system noise.
    • Ensure that the hose connections are tight.
    • Ensure that air is not leaking into the system through loose connections.

Bleeding Procedure

  1. Turn the key to the OFF position.
  2. Turn the steering wheel full left.
  3. Fill the fluid reservoir to the FULL COLD level.
  4. Leave the cap off.

  5. Raise the front wheels off of the ground.
  6. With an assistant checking the fluid level and the condition, turn the steering wheel lock-to-lock at least 20 times.
  7. The power remains OFF.

    5.1. On systems with long return lines or fluid coolers, turn the steering wheel lock-to-lock at least 40 times.
    5.2. Trapped air may cause the fluid to overflow.

    Clean any spilled fluid in order to allow for a leak inspection.

    5.3. Keep the fluid level at FULL COLD.
    5.4. Be alert to periodic bubbles that may indicate a loose connection or a leaking O-ring seal.
  8. Inspect the fluid constantly while you turn the wheel.
  9. Ensure that there are no bubbles.
  10. If there are any bubbles, re-inspect the connections. Repeat Step 5.

  11. Return the wheels to the center.
  12. Lower the front wheels to the ground.
  13. Keep the power ON for two minutes.
  14. Turn the steering wheel in both directions.
  15. Important: Verify the following conditions:

       • A smooth power assist
       • A noiseless operation
       • A proper fluid level
       • Absence of system leaks
       • A proper fluid condition

  16. The procedure is complete if all of the proper conditions apply.
  17. If the conditions still exist, refer to Special Conditions.

Special Conditions

  1. Ensure that the fluid is free of bubbles and discoloration.
  2. If either condition is evident, use the following procedure:

    1.1. Turn the power OFF.
    1.2. Wait two minutes.
    1.3. Recheck the hose connections.
    1.4. Repeat Steps 8-14.
    1.5. If the condition still exists, replace the O-ring seals and the hose clamp.
    1.6. Fill the system.
    1.7. Repeat the bleeding procedure.
  3. If you hear a pump whine or groan, turn the power ON and inspect the hoses for contact with the frame body or the drive motor.
  4. If no contact is found, use either of the following methods in order to cool down the fluid and repressurize the system.

  5. Replace the power steering pump if the noise persists.
  6. Repeat the bleed procedure following pump replacement.
  7. • Normal cool down.
         1. Turn OFF the power.
         2. Allow the system to cool.
         3. Install the reservoir cap.
    • Partial fluid replacement
         1. Turn the key to the OFF position.
         2. Remove the fluid from the reservoir using a suction device.
         3. Refill the reservoir with cool, clean fluid.
         4. Install the reservoir cap.