GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC K Sierra - 4WD 🢒 Steering 🢒 Power Steering System 🢒 Power Steering System Bleeding

Bleed Procedure

Tools Required

    • J 35555 Mity Vac
    • J 43485 Power Steering Bleeder Adapter
    • Bleed the steering system for the following reasons:
       - Components replaced
       - Fluid line disconnected
       - Steering system noise occurs
       - Prevention of pump damage
       - Proper system operation

       Important: Use clean, new power steering fluid type only.

    • See the Maintenance Lubrication subsection for fluid specifications.

       Important: Hoses touching the frame, body or engine can cause system noise.

    • The hoses must not touch any other part of the vehicle.

       Important: Loose connections may not leak, but could allow air into the steering system.

    • Verify that all hose connections are tight.

    Object Number: 443644 Size: SH

    Important: Maintain the fluid level throughout the bleed procedure.

  1. Remove the pump reservoir cap.
  2. Fill the pump reservoir with fluid to the "FULL COLD" level.

    3. Object Number: 443646 Size: SH
  3. Attach J 43485 toJ 35555 or equivalent.
  4. Place J 43485 on the pump reservoir filler neck.
  5. Apply a vacuum of 20 Hg maximum.
  6. Wait 5 minutes. Typical vacuum drop is 2-3 in Hg. If the vacuum does not remain steady, see Special Conditions at the end of this procedure.
  7. Reinstall the pump reservoir cap.
  8. Start the engine. Allow the engine to idle.
  9. Turn off the engine.
  10. Verify the fluid level. Repeat steps 8 through 10 until fluid stabilizes.
  11. Start the engine. Allow the engine to idle.

    12. Important: Do not turn steering wheel to lock.

  12. Turn the steering wheel 180-360 degrees in both directions 5 times.
  13. Switch the ignition off.
  14. Verify the fluid level.

    15. Object Number: 443644 Size: SH
  15. Remove the pump reservoir cap.

    16. Object Number: 443646 Size: SH
  16. Attach J 43485 to J 35555 or equivalent.
  17. Place J 43485 on the pump reservoir filler neck.
  18. Apply a vacuum of 20 Hg maximum.
  19. Wait 5 minutes.
  20. Verify the fluid level.

    21. Object Number: 443656 Size: SH
  21. Reinstall the pump reservoir cap.

Special Conditions Procedure

Tools Required

    • J 35555 Mity Vac
    • J 43485 Power Steering Bleed Adapter

    Object Number: 443667 Size: SH
  1. If the vacuum continues to drop, remove the pressure and return hose from the pump.
  2. Install the plugs (1) (2) supplied with J 43485 into the pressure and return port.

    3. Object Number: 443646 Size: SH
  3. Attach J 43485 to J 35555 or equivalent.
  4. Place J 43485 on the pump reservoir filler neck.
  5. Apply a vacuum of 20 Hg maximum.
  6. If the vacuum drops again, repair or replace the pump. If the vacuum holds steady, continue to check the other parts of the steering system.

    7. Important: Fluid must be free from bubbles. Be aware of periodic bubbles that indicate a loose connection or leaking O-ring seal in the return hose or the pressure hose.

    Important: Fluid must be free from discoloration.

  7. Observe the fluid.
  8. If condition persists, replace the following parts:
    9. • The return hose clamps
    • The return hose O-rings
    • The pressure hose O-rings
    • The gear cylinder line O-rings
    • The reservoir to pump O-ring
  9. Repeat the bleed procedure from the beginning.
  10. Drive the vehicle approximately 16 kilometers (10 miles) to warm the system to operating temperature. Evaluate vehicle on a smooth flat surface.
  11. To check for noise problems, verify the following items:
    12. • There is smooth power assist.
    • The vehicle operates quietly.
    • The pump maintains the proper fluid level.
    • There is no leaking in the steering system.
    • The fluid is free of foam or discoloration.