Hydraulic Test

MEASURE LINE PRESSURE





NOTICE: Perform the test at normal operating fluid temperature (50 - 80°C or 122 - 176°F)

(a) Warm up the transmission fluid.
(b) Remove the transmission case test plug and connect the hydraulic pressure gauge.
SST O9992-OOO94 (Oil pressure gauge)
(c) Fully apply the parking brake and chock the tour wheels.
(d) Start the engine and check idling rpm.
(e) Step down strongly on the brake pedal with your left foot and shift into D range.
(f) Measure the line pressure when the engine is idling.
(g) Press the accelerator pedal all the way down.
Quickly read the highest line pressure when engine speed reaches stall speed.
(h) In the same manner, perform the test in R range.

Line Pressure Specifications:

If the measured pressures are not up to specified values, recheck the throttle cable adjustment and perform a retest.

EVALUATION
(a) If the measured values at all ranges are higher than specified:
^ Throttle cable out of adjustment
^ Throttle valve detective
^ Regulator valve defective

(b) If the measured values at all ranges are lower than specified:
^ Throttle cable out of adjustment
^ Throttle valve defective
^ Regulator valve defective
^ Oil pump defective
^ O/D direct clutch defective

(c) If pressure is low in the D range only:
^ D range circuit fluid leakage
^ Front clutch defective

(d) If pressure is low in the R range only:
^ R range circuit fluid leakage
^ Rear clutch defective first and reverse brake defective


MEASURE GOVERNOR PRESSURE





NOTICE: Perform the test at normal operating fluid temperature (50 - 80°C or 122 - 176°F).
Measurement can be made with a 1,000 rpm test, but if tests are to be made at 1,800 rpm and 3,500 rpm, it would be safer to do it on road or using a chassis dynamometer because an on-stand test could be hazardous.

(a) Warm up the transmission fluid.
(b) Lock the center differential.
(c) Remove front propeller shaft.
(d) Jack up the vehicle and support it on stands.
(e) Remove the transmission case test plug and connect the hydraulic pressure gauge.
SST 09992-00094 (Oil pressure gauge)
(f) Check that the parking brake is not applied.
(g) Start the engine.
(h) Shift into the D range and measure the governor pressure at the speeds specified in the table.

Governor Pressure Specifications:

EVALUATION
If governor pressure is defective:
^ Line pressure defective
^ Fluid leakage in governor pressure circuit governor valve operation defective