LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2008 >> GS 460 >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle >> Automatic Transmission System >> Hydraulic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Hydraulic Test

  1. MEASURE LINE PRESSURE CAUTION: 

    The line pressure test should always be carried out in pairs. One technician should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is performing the test.

    NOTE:
    • Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F)
    • Be careful to prevent SST hose from interfering with the exhaust pipe.
    • This Check must be conducted after checking and adjusting engine.
    • Perform under condition that A/C is OFF.
    • When conducting stall test, do not continue more than 5 seconds.
      Fig 1: Measuring Line Pressure With SST
      G04948272Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Warm up the ATF.
    2. Remove the test plug on the transmission case center right side and connect SST.

      SST 09992-00095 (09992-00231, 09992-00271) 

    3. Fully apply the parking brake and chock the 4 wheels.
    4. Start the engine and check the idling speed.
    5. Keep your left foot firmly on the brake pedal and move the shift lever to D.
    6. Measure the line pressure when the engine is idling.
    7. Depress the accelerator pedal as much as possible with your right foot. Quickly read the highest line pressure reading when the engine speed reaches stall speed.
    8. Perform the measure line pressure test again with the shift lever on R.

      Specified line pressure: 

      LINE PRESSURE SPECIFICATION

      Condition D position kPa (kgf / cm2 , psi) R position kPa (kgf/cm2 , psi)
      Idling 365 to 435 kPa (3.7 to 4.4 kgf/cm2 , 53 to 63 psi) 375 to 445 kPa (3.8 to 4.5 kgf/cm2 , 54 to 65 psi)
      Stall test 1410 to 1610 kPa (14.4 to 16.4 kgf/cm2 , 205 to 234 psi) 1500 to 1700 kPa (15.3 to 17.3 kgf/cm2 , 218 to 247 psi)

      Evaluation: 

      TEST RESULT POSSIBLE CAUSE

      Problem Possible Cause
      Measured values at all positions are higher than specified
      • Shift solenoid valve SLT defective
      • Regulator valve defective
      Measured values at all positions are lower than specified
      • Shift solenoid valve SLT defective
      • Regulator valve defective
      • Oil pump defective
      Pressure is low when shift lever is on D only
      • D position circuit fluid leak
      • C1 clutch defective
      Pressure is low when shift lever is on R only
      • R position circuit fluid leak
      • C4 clutch defective
      • B2 brake defective
scientia non olet · About LEMON Manuals