Hydraulic Pressure Test

Bring the transmission fluid to normal operating temperature.


Connect a pressure test gauge (A) to the test port (B) on the passenger side of the transmission. The gauge should have a capacity of 300 psi or 2100 kpa.


Apply the parking brakes and block the wheels.


WARNING: Do not allow anyone to stand at the front or rear of the vehicle while performing the following steps in the pressure test.


Check and adjust engine curb idle speed. Apply the service brakes.


Shift the transmission into D range and note line pressure with the engine at curb idle speed. Pressure should be 53-to-61 psi (363-to-422 kPa).


Press the accelerator to the wide open throttle position and note line pressure. Pressure should be 161-to-196 psi (1108-to-1353 kpa) at wide open throttle.


CAUTION: Do not maintain wide open throttle for more than three or four seconds at a time.


Shift the transmission into Reverse and note line pressure with the engine at curb idle speed. Pressure should be 73-to-87 psi (500-to-598 kpa).

Press the accelerator to the wide open throttle position and note line pressure in Reverse. Pressure should be 223-to-273 psi (1540-to-1883 kPa).


CAUTION: Do not maintain wide open throttle for more than three or four seconds at a time.


If line pressure is not within specifications, adjust the line pressure cable and repeat the pressure test.


Pressure Test Analysis


If pressures in D and Reverse are higher than specified, check for the following:


Line pressure cable loose, worn, binding or out of adjustment


Throttle valve, downshift plug, throttle cam sticking, worn or damaged


Primary regulator valve sticking, worn, or damaged


If pressures in D and Reverse are lower than specified, check for the following:


Line pressure cable loose, worn, binding or out of adjustment


Throttle valve, downshift plug, throttle cam sticking, worn or damaged

Primary regulator valve sticking, worn, or damaged


Oil pump gears or housing worn or damaged


Overdrive clutch worn or damaged

If pressures are low in D range only, check for the following:


Forward clutch worn or damaged


Fluid leakage in D range circuit (component seal and O-rings)

If pressures are low in Reverse only, check for the following:

Shift linkage (and manual valve) out of adjustment

Fluid leakage in Reverse circuit (component seal and O-rings)

Direct clutch worn or damaged

First/Reverse brake worn or damaged