GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 21867 Pressure Gage
    • J-21867-50 Transmission Line Pressure Adapter

The hydraulic test can inspect the working condition inside the automatic transmission (A/T) by measuring line pressure in drive (D)/reverse (R) range and idle/stall condition.


    Object Number: 1245752  Size: SH
  1. Wedge the 4 wheels and apply the parking brake fully. Lock the vehicle in place.
  2. Install J 21867 and J-21867-50 to test the hole (1) for line pressure.
  3. Important: Do not continuously run longer than 5 seconds. Extreme increasing of oil temperature may occur.

  4. Fully press on the brake pedal with left foot, shift into drive (D) and reverse (R) range and measure the line pressure idle/stall condition.
  5. Specifications

        • The engine idle line pressure in drive (D) is 0.14-0.37 mPa (20.30-53.70 psi).
        • The engine idle line pressure in reverse (R) is 0.59-0.68 mPa (85.60-98.62 psi).
        • The engine stall line pressure in drive (D) is 1.10-1.23 mPa (159.54-178.40 psi).
        • The engine stall line pressure in reverse (R) is 1.58-1.83 mPa (229.16-265.41 psi).

Make sure to keep interval for more than 1 minute between stall tests.

Make sure to check that there is no oil leak after installing J 21867 and J-21867-50 .

Result of Hydraulic Test

Cause of Failure

Higher than standards in both drive (D) and reverse (R)

    • Pressure control solenoid (PCS) failure
    • Primary regulator valve failure

Lower than standards in both drive (D) and reverse (R)

    • PCS failure
    • Primary regulator valve failure
    • Oil pump failure
    • Oil strainer failure, clogging
    • Oil leak for each range circuit

Lower than standards only in drive (D)

    • Drive (D) hydraulic circuit failure
    • Forward clutch (C1) failure

Lower than standards only in reverse (R)

    • Reverse (R) hydraulic circuit failure
    • Reverse clutch (C3) failure
    • 1st and reverse brake (B3) failure