LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2006 >> LS 430 >> Repair and Diagnosis >> Steering >> Manual Steering >> Power Steering >> Power Steering System >> On-Vehicle Inspection

On-Vehicle Inspection

  1. INSPECT DRIVE BELT 
    1. Visually check the belt for excessive wear, frayed cords, etc.

    If any defect is found, replace the drive belt.

    HINT:

    Cracks on the rib side of a belt are considered acceptable. Replace the belt if there are any missing ribs.

    Fig 1: Inspecting Drive Belt (1 Of 2)
    G02999483Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    Fig 2: Inspecting Drive Belt (2 Of 2)
    G02999484Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. CHECK FLUID LEVEL 
    1. Keep the vehicle level.
    2. With the engine stopped, check the fluid level in the oil reservoir. If necessary, add fluid.
      1. Fluid: ATF DEXRON® II or III 
      Fig 3: Checking Fluid Level In Oil Reservoir
      G02999485Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      When hot, check that the fluid level is within the HOT LEVEL range on the reservoir.

      If the fluid is cold, check that it is within the COLD LEVEL range.

    3. Start the engine and run at idle.
    4. Turn the steering wheel from lock to lock several times to raise fluid temperature.
      1. Fluid temperature: 75 to 80°C (167 to 176°F) 
    5. Check for foaming or emulsification.

      If foaming or emulsification is identified, bleed air in the power steering system (see step 3).

      Fig 4: Checking For Foaming Or Emulsification
      G02999486Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. With the engine idling, measure the fluid level in the reservoir.
      Fig 5: Measuring Fluid In Reservoir (With Engine Idling)
      G02999487Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Stop the engine.
    8. Wait a few minutes and measure the fluid level in the reservoir again.
      1. Maximum fluid level rise: 5 mm (0.20 in.) or less 

      If the fluid level rise exceeds the maximum, bleed air in the power steering system (see step 3).

    9. Check the fluid level.
  3. BLEED AIR IN POWER STEERING SYSTEM 
    NOTE: If you replace or separate the components for power steering oil pressure line, bleed air in the power steering system after the operation.
    1. Idle the engine at 1,000 rpm or less until bubbles in the fluid disappear. (Be sure not to turn the steering wheel.)
    2. When the bubbles disappear, slowly turn the steering wheel from lock to lock 2 or 3 times.
    3. Repeat procedures (a) and (b) until the fluid level in the reservoir becomes stable and bubbles disappear. If the fluid level goes below the MAX line, add fluid.
    4. When the fluid level becomes stable, increase and decrease oil pressure 2 or 3 times for both left and right by turning the steering wheel to the full lock positions and jiggling it there.
    5. Make sure that no bubbles exist in the reservoir. When turning the steering wheel quickly or turning it from lock to lock position, check that the steering wheel is not heavy to turn and there is no abnormal noise or vibration.
    6. When there are fluid leaks or abnormalities after bleeding air, repair them and repeat procedures (a) to (e). If the abnormalities still exist, replace the related parts.
    Fig 6: Bleeding Air In Power Steering System
    G02999488Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. CHECK STEERING FLUID PRESSURE 
    1. Put a wrench on the pressure feed tube hose to secure it.
    2. Put SST on the flare nut as shown in Fig 7 .
      1. SST 09023-12700
      Fig 7: Installing SST On Flare Nut
      G02999489Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Joint a spinner handle to the SST.

      HINT:

      Use an extension bar or universal joint according to a situation.

    4. Loosen and disconnect the pressure feed tube.
    5. Connect SST, as shown in Fig 8 .
      1. SST 09640-10010 (09641-01010, 09641-01030, 09641-01040)
      Fig 8: Connecting SST
      G02999490Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE: Check that the valve of the SST is in the open position.
    6. Bleed air in the power steering system (see step  2).
    7. Start the engine and run at idle.
    8. Turn the steering wheel from lock to lock several times to raise fluid temperature.
      1. Fluid temperature: 75 to 80°C (167 to 176°F) 
    9. With the engine idling, close the valve of the SST and observe the reading on the SST.
      1. Standard fluid pressure: 8,336 to 8,826 kPa (85 to 90 kgf/cm 2  , 1,209 to 1,280 psi) 
      NOTE:
      • Do not keep the valve closed for more than 10 seconds.
      • Do not allow the fluid temperature to become too high.
      Fig 9: Observing Reading On SST Closing Valve
      G02999491Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    10. With the engine idling, fully open the valve.
      Fig 10: Fully Opening Valve (With Engine Idling)
      G02999492Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    11. Measure the fluid pressure at engine speeds of 1,000 rpm and 3,000 rpm.
      1. Standard fluid pressure difference: 490 kPa (5 kgf/cm 2  , 71 psi) or less 
      NOTE: Do not turn the steering wheel.

      If the observed value exceeds the standard, check the flow control valve.

    12. With the engine idling and the valve fully opened, turn the steering wheel to the right or left full lock position.
      1. Standard fluid pressure: 8,336 to 8,826 kPa (85 to 90 kgf/cm 2  , 1,209 to 1,280 psi) 
        Fig 11: Turning Steering Wheel To Right Or Left Full Lock Position
        G02999493Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:
      • Do not keep the steering wheel in the full lock position for more than 10 seconds.
      • Do not allow the fluid temperature to become too high.
    13. Disconnect the SST.
      1. SST 09640-10010 (09641-01010, 09641-01030, 09641-01040)
    14. Connect the pressure feed tube.
    15. Put a wrench on the pressure feed tube hose side to hold it.
    16. Put SST on the flare nut as shown in Fig 12 .
      1. SST 09023-12700
      Fig 12: Putting SST On Flare Nut
      G02999494Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    17. Using a torque wrench, tighten the flare nut.
      1. Torque: 40 N.m (410 kgf.cm, 30 ft.lbf) 

      HINT:

      • Use a torque wrench with a fulcrum length of 345 mm (13.58 in.).
      • This torque value is effective when SST is parallel to the torque wrench.
    18. Bleed air in the power steering system (see step  2).
  5. CHECK AIR CONTROL VALVE 
    1. Turn the air conditioning switch off.
    2. Start the engine and run at idle.
    3. Fully turn the steering wheel.
    4. Check the air control valve.
      1. Pinch the vacuum hose of the air control valve.
        1. Standard: 
        2. The engine speed decreases. 
      2. Release the vacuum hose of the air control valve.
        1. Standard: 
        2. The engine speed increases. 

        If engine speed does not change as specified, check and repair or replace the air control valve and vacuum hoses.

        If you replace the air control valve, tighten it to the specified torque.

        1. Torque: 31.4 to 41.2 N.m (320 to 420 kgf.cm, 23 to 30 ft.lbf) 
      Fig 13: Checking Air Control Valve
      G02999495Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. CHECK STEERING EFFORT 
    1. Center the steering wheel.
    2. Remove the horn button assy (see step 5 in REPLACEMENT ).
    3. Start the engine and run at idle.
    4. Measure the steering effort in both directions.
      1. Steering effort (Reference): 6.9 N.m (70 kgf.cm, 61 in.lbf) or less 

      HINT:

      Check tire type, pressure and road surface before making a diagnosis.

      Fig 14: Measuring Steering Effort
      G02999496Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    5. Disconnect the PPS solenoid connector.
      Fig 15: Disconnecting PPS Solenoid Connector
      G02999497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    6. Measure steering effort in both directions.
      1. Standard: 
      2. Steering effort is heavier than the reference values in procedure (d), and that the power assist is operating. 
      3. If steering effort is not as specified, check the PPS solenoid valve (see PPS LINEAR SOLENOID CIRCUIT ).
    7. Connect the PPS solenoid connector.
    8. Check that the steering wheel assy set nut is tightened.
      1. Torque: 50 N.m (510 kgf.cm, 37 ft.lbf) 
    9. Install the horn button (see step 6 in REPLACEMENT ).