Hydraulic Test

UF1AE TRANSFER: FOUR WHEEL DRIVE CONTROL SYSTEM: HYDRAULIC TEST

HYDRAULIC TEST

1. PERFORM LINE PRESSURE TEST
(a) Measure the line pressure.
HINT:
- Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F).
- The line pressure test should always be performed in pairs. One technician should observe the conditions of the wheels or wheel chocks outside the vehicle while the other is performing the test.
- Be careful to prevent SST hose from interfering with the exhaust pipe.
- This check must be performed after ensuring that the engine is running properly.
- Perform this test while the A/C is OFF.
- When performing the stall test, do not continue more than 5 seconds.
(1) Warm up the ATF (Automatic Transmission Fluid).
(2) Lift the vehicle up.

(3) Remove the test plug on the transfer case and connect the SST.
SST: 09992-00095 (09992-00231, 09992-00271)
(4) Lower the vehicle.
(5) Fully apply the parking brake and chock the 4 wheels.
(6) Start the engine and check idling speed.
(7) Keep your left foot pressing the brake pedal firmly and move the shift lever to the D position.
(8) Measure the line pressure when the engine is idling.
(9) Depress the accelerator pedal all the way down. Read the highest line pressure as quickly as possible when the engine speed reaches stall speed.
(10) In the same manner, perform the test with the shift lever in the R position.

Specified line pressure:

2. PERFORM CENTER DIFFERENTIAL OPERATING HYDRAULIC PRESSURE TEST
(a) Measure the center differential operating hydraulic pressure.
HINT:
- Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F).
- The line pressure test should always be performed in pairs. One technician should observe the conditions of the wheels or wheel chocks outside the vehicle while the other is performing the test.
- Be careful to prevent SST hose from interfering with the exhaust pipe.
- This check must be performed after ensuring that the engine is running properly.
- Perform this test while the A/C is OFF.
- When performing the stall test, do not continue more than 5 seconds.
(1) Warm up the ATF (Automatic Transmission Fluid).
(2) Lift the vehicle up.

HINT:
Begin the test with the steering wheel centered.

(10) Check that the center differential operating hydraulic pressure drops when the engine reaches stall speed and the steering wheel is turned 140° to the left or right.