Jeep Cherokee

 Service Manual

Transmission and transfer case » AW-4 automatic transmission » Diagnosis and testing
Hydraulic pressure test

Pressure Test Procedure

(1) Connect pressure test gauge to test port on passenger side of transmission (Fig. 39). Use Adapter 7554 to connect gauge. Be sure test gauge has minimum capacity of 300 psi (2100 kPa).

(2) Be sure transmission fluid is at normal operating temperature.

(3) Apply parking brakes and block 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.

(4) Check and adjust engine curb idle speed.

(5) Apply (and hold) service brakes.

Fig. 39 Pressure Test Gauge Connection

1 - PRESSURE GAUGE
2 - TEST PORT

(6) Shift transmission into D range and note line pressure with engine at curb idle speed. Pressure should be 61-to-70 psi (421-to-481 kPa).

(7) Press accelerator pedal to wide open throttle position and note line pressure. Pressure should be 173-to-209 psi (1196-to-1442 kPa).

CAUTION: Do not hold wide open throttle for more than 3-4 seconds at a time.

(8) Shift transmission into Reverse and note line pressure with engine at curb idle speed. Pressure should be 75-to-90 psi (519-to-618 kPa).

(9) Press accelerator to wide open throttle position and note line pressure in Reverse. Pressure should be 213-to-263 psi (1471-to-1814 kPa).

CAUTION: Do not hold wide open throttle for more than 4 seconds.

(10) If line pressure is not within specifications, adjust transmission throttle cable and repeat pressure test.

General diagnosis information

Effects of incorrect fluid level

Causes of burnt fluid

Fluid contamination

Preliminary inspection and adjustment

Manual shifting test

Hydraulic pressure test

Pressure test analysis

Time lag test

Test procedure

Time lag test analysis

Service diagnosis

Transmission solenoid testing

Park/neutral position switch

Gearshift cable

Throttle valve cable

Speed sensor testing

Flow testing transmission main cooler

Torque converter stator clutch inspection