Hydraulic Pressure Test

HYDRAULIC PRESSURE TEST
Pressure Test Procedure

Pressure Test Gauge Connection:

1. Connect pressure test gauge to test port on passenger side of transmission. 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.
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.

PRESSURE TEST ANALYSIS
If pressures in D and Reverse are higher than specified in test, check for the following:
- throttle cable loose, worn, binding or out of adjustment
- throttle valve, downshift plug, throttle cam, or primary regulator valve are sticking, worn or damaged
If pressures in D and Reverse are lower than specified in test, check for following:
- throttle cable loose, worn, binding or out of adjustment
- throttle valve, downshift plug, or 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 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 following:
- Shift cable 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