Hydraulic Test

HYDRAULIC TEST

PREPARATION
a. Warm up the transaxle fluid.
b. Remove the transaxle case test plug and connect the hydraulic pressure gauge.
SST 09992-00094 (Oil pressure gauge)

CAUTION:
- Perform the test at normal operating fluid temperature (122 - 176°F or 50 - 80°C)
- The line pressure test should always be carried out in pairs. One should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is performing the test.






MEASURE LINE PRESSURE
a. Fully apply the parking brake and chock the four wheels.
b. Start the engine and check idling rpm.
c. Step down strongly on the brake pedal with your left foot and shift into D range.
d. Measure the line pressure when the engine is idling.
e. Press the accelerator pedal all the way down. Quickly read the highest line pressure when engine speed reaches stall speed.
f. In the same manner, perform the test in R range.

A540H:

If the measured pressure 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 defective
- 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
- Forward clutch defective

d. If pressure is low in the R range only:
- R range circuit fluid leakage
- Direct clutch defective
- First and reverse brake defective


MEASURE CENTER DIFFERENTIAL CONTROL PRESSURE



a. Warm up the transaxle fluid (122 - 176°F or 50 - 80°C)
b. Measure the line pressure.
c. Remove the transfer case test plug and mount the oil pressure gauge (SST).
SST 09992-00094
d. Check the parking brake to see that it is fully applied chock the four wheels.
e. Disconnect the connector from ECT ECU.
f. Start the engine.
g. Apply battery voltage to terminal SD1 or SD2 of the wire harness side connector and turn the No.1 and No.2 center differential control solenoid valves to either ON or OFF.
h. Shift into the L range, step down strongly on the brake pedal with your left foot and while manipulating the accelerator pedal with the right foot, measure the pressure at the engine speeds specified in the table.





NOTE: After inspecting the center differential control pressure, erase the diagnosis codes (No.73 and 74) from the memory.