GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 25323-D Power Steering System Analyzer


Object Number: 585988  Size: SH

    Important: Ensure that the suspension system components are not binding.

    Ensure that all of the power steering hose connections are tight. Loose connections may allow air to leak into the power steering system.

  1. Turn the ignition OFF.
  2. Place a drain pan under the vehicle in order to catch any power steering fluid.
  3. Disconnect the power steering pressure line (2) from the power steering pump or the power steering gear as necessary. Refer to Power Steering Pressure Pipe/Hose Replacement .
  4. Install the J 25323-D between the power steering pump and the power steering gear. Adapters may be required (1) .
  5. Inspect and add ONLY approved power steering fluid as necessary in order to ensure that the power steering fluid is at the FULL COLD level. Refer to Checking and Adding Power Steering Fluid .
  6. Fully open the J 25323-D valve.
  7. Start the engine.
  8. Notice: Do not hold the steering wheel in the full turn position longer than 5 seconds, as damage to the steering pump may result.

  9. Turn the steering wheel and BRIEFLY hold the steering wheel against the steering stop in order to release any trapped air from the system.
  10. Inspect and ensure that all of the power steering connections are not leaking. Refer to
  11. Pressure readings in excess of 1379 kpa (200 psi) COULD indicate a restriction in the power steering system. If the reading exceeds 1379 kpa (200 psi), turn the engine off IMMEDIATELY. Locate and repair the restriction, then retest the system.

  12. Inspect and add ONLY approved power steering fluid as necessary in order to ensure that the power steering fluid is at the FULL COLD level. Refer to Checking and Adding Power Steering Fluid .
  13. Allow the engine to run until the engine reaches full operating temperature.
  14. Record the pressure reading and flow reading (if applicable).
  15. If you are using the J 25323-D , partially close the valve until the system pressure reaches 4827 kpa (700 psi), then record the FLOW reading. Subtract this flow reading from the flow reading recorded in Step 12.
  16. If the flow DECREASE is more than 3.8 liters per minute (1 gallon per minute), there is a power steering pump internal leak. Replace the power steering pump. Refer to Power Steering Pump Replacement .

    Notice: Do not leave the valve fully closed for more than 5 seconds, or the pump could be damaged internally.

  17. Fully close then open the J 25323-D valve three times and record all of the high pressure readings.
  18. The power steering system pressure relief specifications for this vehicle is 8274-8964 kpa (1200-1300 PSI).

    • If the three high pressure readings are within specifications and not more than 245 kpa (50 psi) of each other, the system is operating properly.
    • If the three high pressure readings are within specifications, but NOT within 245 kpa (50 psi) of each other, inspect the power steering flow control valve. Perform the following steps:
         1. Remove the power steering pump flow control valve. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle .
         2. Inspect the flow control valve.

    If any burrs or scratches are noticed on the flow control valve, replace the flow control valve. Do NOT attempt to clean the flow control valve.

    If any burrs or scratches are noticed in the control valve bore, replace the power steering pump. Refer to Power Steering Pump Replacement .

         3. Inspect the power steering fluid.

    If the power steering fluid is clean, install the flow control valve and retest the system.

    If the power steering fluid is NOT clean, flush the power steering system and retest the system. Refer to Power Steering System Flushing .

    • If the three high pressure readings are NOT within specifications, but within 245 kpa (50 psi) of each other, replace the power steering pump flow control valve and retest the system. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle .
    • If the system fails the test twice, replace the power steering pump and retest the system. Refer to Power Steering Pump Replacement .
  19. If you are using the J 25323-D , perform the following steps:
  20. 15.1. Increase the engine speed to approximately 1500 RPM and record the flow reading.

    The power steering system high flow specifications for this vehicle is 9.0-11.0 liters per minute (2.4-2.8 gallons per minute).

       • If the difference between the actual flow reading and the maximum flow specification is more than 3.8 liters per minute (1 gallon per minute), remove the power steering flow control valve and inspect the power steering pump flow control valve for any wear or damage. Do NOT disassemble the flow control valve. Replace the flow control valve if the flow control valve is worn or damaged. Refer to Power Steering Pump Flow Control Valve Replacement - Off Vehicle .
       • If the difference between the actual flow reading and the maximum flow specification is less than 3.8 liters per minute (1 gallon per minute) and is NOT within specifications, replace the power steering pump and retest the system. Refer to Power Steering Pump Replacement .

            Notice: Do not hold the steering wheel in the full turn position longer than 5 seconds, as damage to the steering pump may result.

    15.2. Turn the steering wheel from steering stop to steering stop and record the FLOW readings at each stop.
       • If the flow is LOWER than 3.8 liters per minute (1 gallon per minute), the power steering pump and the flow control valve are operating properly.
       • If the flow is HIGHER than 3.8 liters per minute (1 gallon per minute), the power steering gear is leaking across the piston or bypassing the valve circuit. Replace the power steering gear. Refer to Steering Gear Replacement .
  21. Disconnect and remove the J 25323-D from the vehicle.
  22. Connect the power steering pressure line. Refer to Power Steering Pressure Pipe/Hose Replacement .
  23. Bleed the power steering system. Refer to Power Steering System Bleeding .
  24. Inspect the power steering system and ensure that there are no fluid leaks. Refer to Power Steering Gear and Pump Leaks .