Pressure Test

PRESSURE TESTING



- Location of pressure test port.
- Always replace pressure plugs as they are self-sealing bolts.

LINE PRESSURE TEST PROCEDURE
1. Check A/T and engine fluid levels. If necessary, add fluid.



2. Warm up engine until engine oil and A.T.F. reach operating temperature; after vehicle has been driven approx. 10 minutes.

A.T.F. operating temperature: 50 - 80°C (122 - 176°F)




3. Install pressure gauge to line pressure port.




4. Set parking brake and block wheels.
Continue to depress brake pedal fully while performing line pressure test at stall speed.




5. Start engine and measure line pressure at idle and stall speed.

JUDGMENT OF LINE PRESSURE TEST
- If line pressure does not rise, first check to make sure that throttle wire is connected properly.

1. When line pressure while idling is low at all positions ("D", "2", "1", "R" and "P"), the problem may be due to:
- Wear on interior of oil pump
- Oil leakage at or around oil pump, control valve body, transmission case or governor
- Sticking pressure regulator valve
- Sticking pressure modifier valve

2. When line pressure while idling is low at a particular position, the problem may be due to the following:
- If oil leaks at or around low & reverse brake circuit, line pressure becomes low in "R" range but is normal in "P", "D", "2" or "1" range.

3. When line pressure is high while idling, pressure regulator valve may have stuck.

GOVERNOR PRESSURE TESTING




1. Check A/T and engine fluid levels. If necessary, add fluid.
2. Warm up engine until engine oil and A.T.F. reach operating temperature; after vehicle has been driven approx. 10 minutes.

A.T.F. operating temperature: 50 - 80°C (122 - 176°F)




3. Install pressure gauge to governor pressure port.




4. Set parking brake and block rear wheels.
5. Jack up front wheels.
6. Set selector lever in D range and drive vehicle.
Be careful of rotating wheels.

Governor pressure:



- Governor pressure is not generated when vehicle is stopped. (front wheels are not rotating.)
- Governor pressure rises gradually in response to vehicle speed. (front wheel rotating speed.)

- If not, check governor valve assembly. Refer to "DISASSEMBLY"