A/T - Cleaning Hydraulic System Components
87nissan06Models All Models
Section Automatic Transmission
Classification AT87-008
Bulletin No. TS87-172
Date November 23, 1987
CLEANING AUTOMATIC TRANSMISSION COMPONENTS
APPLIED MODELS: All Nissan models equipped with automatic transmission or transaxle
SERVICE INFORMATION
Under severe service, some automatic transmissions or transaxles may become contaminated with burned fluid, clutch and brake material, or metal particles, all of which can cause reduced efficiency or damage. If the damage is not so extensive as to warrant transmission overhaul, use the following procedures to clean the contaminants out of the hydraulic system components before replacing the fluid.
IN-VEHICLE FLUID CHANGE/FLUSH
If the transmission or transaxle is contaminated with burned oil or clutch and band material, all fluid, including the fluid in the torque converter, must be changed and the transmission flushed out. Drain and replace the the old fluid and use the following procedure to flush the assembly.
1. Disconnect the transmission oil cooling lines at the radiator heat exchanger.
2. Block the transmission oil return line. Connect a rubber line to the disconnected transmission oil "out" line and place the rubber line into a suitable oil drain pan.
3. Start the engine and allow the vehicle to run at idle in "PARK." Oil will now be discharged out of the transmission oil cooler line.
4. Place a filler funnel into the transmission filler tube and slowly fill the transmission with new automatic transmission fluid. Replace the fluid at approximately the same rate that it is discharged out of the oil cooler line. This will be about 3 or 4 quarts per minute.
CAUTION: DO NOT ALLOW THE TRANSMISSION TO RUN OUT OF FLUID. DAMAGE TO INTERNAL COMPONENTS COULD RESULT.
5. Run the engine and allow the flushing process to continue until the fluid discharged out of the oil cooler line is clear. This will require a total of about 7 quarts of fluid flushed through the system.
6. Stop the engine and perform the Oil Cooler/Heat Exchanger Cleaning Procedure described below.
7. After the flushing is completed, re-connect the oil cooler lines. Re-start the engine and check for transmission fluid level. Refill as necessary.
OIL COOLER/HEAT EXCHANGER CLEANING PROCEDURE
If contaminants are found in the automatic transmission, there will also be contaminants in the oil cooler. Therefore, the cooler must be flushed or the materials that are present will find their way into the clean transmission. To flush the heat exchanger, use clean solvent in the following procedure.
1. Connect two long hoses (approximately 4 ') onto the radiator heat exchanger fittings.
2. Place one end of the hose onto the solvent discharge line of your shop solvent tank.
3. Run the second line back into the solvent tank.
4. Start the pump on the solvent tank and allow the solvent to flow for a minimum of ten minutes.
5. Disconnect the hoses at the radiator heat exchanger. Blow the heat exchanger out with compressed air at low pressure (10 psi maximum). Then reinstall the automatic transmission cooler lines.