Automatic transmission fluid check
Checking for leaks and fluid levels
Check for leakage and check fluid level.
Checking Fluid Condition
Fluid condition | Probable Cause | Remedy |
Deposition of sticky films | Burning clutches, brakes | Change the automatic transmission fluid and check for faults in the automatic transmission assembly and vehicle (electrical wiring, radiator pipes, etc). |
Milky white or hazy | Water has entered the liquid | Change the automatic transmission fluid and check the places where water can penetrate. |
Lots of metal powder impurities | Increased wear of rubbing components in the automatic transmission | Change the automatic transmission fluid and check if the automatic transmission is working properly |
Stationary check
Stationary test procedure
1. Check the automatic transmission fluid and engine oil levels. Top up if necessary.
2. Drive the car for approx. 10 minutes or warm up the automatic transmission fluid and engine oil to operating temperature.
Operating temperature of automatic transmission fluid: 50-80°С
3. Set the parking brake firmly and chock the wheels.
4. Connect the tachometer and position it so that it is visible to the driver during the test.
It is advisable to indicate on the scale the specified range of engine speeds.
5. Start the engine, depress the brake pedal and move the selector lever to the «D».
6. Keeping the brake pedal depressed, gradually depress the accelerator pedal.
7. Quickly record the engine speed readings with the vehicle stationary and immediately remove your foot from the accelerator pedal.
Attention: During the test, do not hold the accelerator pedal depressed for more than 5 seconds.
Engine speed on a stationary car: 2250-2700 rpm
8. Move the selector lever to position «N».
9. Cool the automatic transmission fluid.
Attention: Let the engine run at idle speed. for at least 1 min.
10. Repeat steps 6-9, setting the selector lever to the position «2», «1» And «R».
Evaluation of the test results on a stationary vehicle
The results of the test and the corresponding components that can be damaged are shown in the figure below.
The revolutions of a stationary vehicle are above the norm in the position «D», «2» or «1».
Slip occurs in 1st gear, but not in 2nd and 3rd gears...Low speed freewheel is slipping.
Slip occurs in the following gears:
- 1st to 3rd gear in range «D» and engine braking is active when overdrive is disengaged (indicator is on «O/D OFF»).
- On 1st and 2nd gears in the range «2» and engine braking is active when the accelerator pedal is released (fully closed throttle).
- The forward clutch or freewheel is slipping.
The revolutions of a stationary vehicle are above the norm in the position «R»
Engine braking does not work in the range «1».... The low speed and reverse brake is slipping.
Engine braking operates within a range «1».... The reverse clutch is slipping.
The revolutions of a stationary car are within the normal range:
The vehicle does not reach speeds above 80 km/h. Overrunning clutch stuck in torque converter housing.
Caution: Be careful as the temperature of the automatic transmission fluid rises very high.
Slip occurs in 3rd and 4th gears in the range «D». The high speed clutch is slipping.
Slip occurs in 2nd and 4th gears in range «D» The band brake is slipping.
Engine braking does not work in 2nd and 3rd gears in the range «D», in 2nd gear in the range «2» and in 1st gear in the range «1» when disengaging overdrive (indicator is on «O/D OFF»)... The engine braking clutch is slipping.
The revolutions of a stationary vehicle are below the norm:
Poor acceleration when starting off.... One way clutch sticks in the torque converter.
Main line pressure check
The location of the main line pressure test ports is shown below.
Always replace plugs as they are self-sealing bolts.
Main Line Pressure Check Procedure
1. Check the automatic transmission fluid and engine oil levels. Top up if necessary.
2. Drive the vehicle for approximately 10 minutes, or warm up the engine oil and automatic transmission fluid to operating temperature.
Operating temperature of automatic transmission fluid: 50-80°С.
3. Connect a pressure gauge to the appropriate test port to check the pressure.
4. Engage the parking brake and chock the wheels.
5. Start the engine and measure the pressure in the main line both at idle and stationary vehicle speeds.
Caution: Keep the brake pedal fully depressed while measuring.
When measuring the pressure in the main line at the speed of a stationary vehicle, follow the section «Stationary check».
Main line pressure
Engine RPM | Main line pressure, kPa (kg/cm2) | |
Ranges «D», «2», «1» | Range «R» | |
Turnover x.x. | 500 (5,1) | 778 (7,9) |
RPM of a stationary vehicle | 1159 (11,8) | 1803 (18,4) |
Evaluation of the results of the pressure test in the main line
Score | Probable Cause | |
Low pressure in all ranges |
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Low pressure in only one of the ranges | Fluid pressure leak between range valve and specific clutch
For example, the pressure in the main line: Low in the ranges «R» And «1», but Normal in ranges «D» And «2». Therefore, fluid leakage occurs in or near the low speed and reverse brake circuit. | |
High pressure |
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At the speed of a stationary car | Low pressure |
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